One initial question about this near-weightless novel. Is it raw? And the answer: by no means: it’s very cooked indeed. It’s the fictive equivalent of a microwaveable meal. Everything in this novel has been boiled and boiled until a great cap of foam crowns the pan and all the goodness has leeched out of the vegetables. This is not to say it’s no fun. On the contrary it is a novel with a considerable fizz; an enjoyably quick read. It's all bubbles, though.
The protagonist, Eric Sanderson, wakes up at the beginning of chapter one with total amnesia. He sees a therapist who informs him that he’s had a personality breakdown (and not for the first time) following the death of his girlfriend on holiday the previous year. He gets letters from his former self, instructing him in the ways of bizarre protective rituals, and warning him of terrible dangers. He goes on a search to uncover more.
Of Amnesia as a premise for novel-writing in general and SF in particular Clute and Nicholls have this to say (the entry is actually written by Dave Langford):
Loss of memory, usually inflicted on the protagonist, is a recurring plot device in all forms of fiction .... In genre writing this has become a notorious CLICHÉ: a combined technique of empathy generation and narrative delay, with amnesiac and reader beginning on an equally bewildered footing and together groping towards the character's IDENTITY, empowerment and goals. Examples include Philip José FARMER's The Maker of Universes (1965; rev 1980), Roger ZELAZNY's Nine Princes in Amber (1970), and Colin KAPP's The Patterns of Chaos (1972) -- whose hero's initial amnesia seems arbitrarily imposed and has no particular justification beyond the traditional knock on the head. … A E van VOGT's "Asylum" (1942 ASTOUNDING); Ursula K LE GUIN's City of Illusions (1967); Keith LAUMER's Dinosaur Beach (1971) and The Infinite Cage (1972); Tanith LEE's The Birthgrave (1975 US); Philip E HIGH's Fugitive from Time (1978) and others; the film D.A.R.Y.L. (1985); and Helen S WRIGHT's A Matter of Oaths (1988).Cliché, yes. Yes. A notorious cliché, yes. Hall is aware that his premise is old, and addresses himself to that fact by flashing his intertexts at us: Jaws! Memento! The Matrix! But this doesn’t address the staleness of his premise; and as it happens the illogicality of his central conceit.
What conceit is that? Well, Sanderson soon realizes that he’s in danger (here in the actual world) of being eaten alive by a 'Ludovician', a shark-shaped notional entity (‘one of the many species of purely conceptual fish’ 64). Just to run that past you again. Sanderson, who lives in the real world, is really menaced by a purely conceptual shark. How? Well, there’s some handwaving about ‘the flows of human interaction and the tides of cause and effect’, and some more about the physical interstices of the world, crawlspaces, empty carparks, unused alleys and so on. But, no, it makes no sense; and its senselessness robs the book of force. Sanderson goes on the run; hooks up with the sexy, smart, high-kicking heroine 'Scout' (with whom of course he becomes romantically entangled) and tracks down the evil Mr Smith ripoff, who is named, via Sherlock Holmes and Bill Gates, ‘Mycroft Ward’. He runs about, solves a couple of codes Dan-Browny-like, has various hairsbreadth escapes, and ultimately builds a conceptual boat to chase the shark in exactly the way the characters in Spielberg’s Jaws did, except that they were (according to the logic of the movie) in a real boat chasing a real shark, and Sanderson is in a notional boat chasing a notional shark that is also somehow a real shark in the real world. By some means.
This is crucial, I think. SF is often at its best as an explicitly metaphorical literature. The Matrix itself is an eloquently metaphorical text. That film’s central metaphor articulates the experience of living in our alienating, high-tech world. Hall’s sharky central metaphor doesn’t really articulate anything, beyond the most generic premise of the thriller (‘the bad guys are chasing you’); and, worse, it never escapes muddle in its understanding of how metaphor works.
The romantic sections between the hero and the heroine are very poorly written; but the mystery of ‘what’s going on?’ at the beginning and the thriller elements of chase-and-search in the middle, are well-plotted enough to keep you turning the pages. Also there are various typographical tricks and embellishments: pictures of the shark made out of characters and so on. This sort of thing:
I find the shine goes off these sorts of typsettery fun and games rather quickly, and the overall conception of the book is too friable, flawed and illogical to leave a solid sense of Good Fiction in the head once the final page has been reached. It’s fun. It’s nothing more.
Now, there’s been a lot of buzz about the pantechnicons of cash Hall has been paid for the movie rights to this novel. Good luck to him, on that; and there’s certainly a cinematic feel to the book, which many readers will like. But it is, for all that, a book. Books are made out of words, and Hall doesn’t put his words together very well.
In particular he overwrites; both in the sense that he is unnecessarily prolix and in the sense that his prose is too-too purple. It goes beyond purple, often, into a sort of stylistic shocking-pink. So, this is how Sanderson wakes up:
My eyes slammed themselves capital O open and my neck and shoulders arched back in a huge inward heave, a single world-swallowing lung-gulp of air. Pretty much everything that happens in the book happens in those terms. People don’t breath in this book, they suck lungfuls of air (‘I sucked a lungful of air’ ; ‘I .. sucked air through my fingers’ ; ‘my lungs [were] pulling and heaving under my ribs’ ). TVs don’t fall over; rather ‘the screen threw itself forward with a screaming electric flash … I tried for silent breaths but my breathing and my thinking were all ripped, chopped, torn-up, ragged.’ 
Hall is aiming for intensity, but he is trying too hard. Less is more. That’s such an important principle of writing that I’m going to put it down here a second time. Less is more. It is more effective to write ‘Increasingly vehement bangs were coming from behind the locked door. They stopped suddenly’ than it is to write:
The banging and slamming, clattering and rattling sounds were coming from behind the locked door, and they were building up, growing more and more aggressive … [Then] deep thick silence thundered from behind the closed door. Pure. Heavy. Pregnant. The sound of being stared at. By the same token to describe a kiss as ‘a million volts’ and
somebody let off a box of fireworks in my stomach. I was winded. They went up like a million-coloured bomb is not to describe a kiss very well. Hall’s writing is the prose-style equivalent of adding multiple exclamations marks and underlining a dozen times in different coloured pens. It does not make me like the book. Sometimes his desire for intensity leads him into patches impossible to visualize (‘Dr Randle was more like an electrical storm or some complicated particle reaction than a person’ ). Very often it leads him into the Valley of Appalling Pretensiousness:
God my lips said. The word was stillborn and tiny and bundled away in a sweep of the gale. Many writers have galloped down into that valley; very few have emerged again alive. Hall is MIA. Take this sentence, describing a rainstorm: ‘A dramatic wet sheet broke against the window followed by a haiku of fat rain taps as the wind took a breath.’  You don’t think that reeks of student creative-writing, of trying too hard? I think it does.
Reading The Raw Shark Texts is a question of the point at which the reader first feels the urge to shout ‘ENOUGH ALREADY!’ Will it be when the literalised-metaphorical rainstorm starts bashing (aggressively banging and slamming, clattering and rattling) at you?
And then it was raining, a heavy downpour of letters, words, images, snatches of events …  The rain came down so hard it had a real weight, beating my head and shoulders into a flinch, pouring heavy over my waterlogged clothes and streaming in flukes from my hood and from my elbows and from my etc etc. Maybe it will be when the queasily staggering prose reaches the following particularly spewy moment? ‘My insides were hanging slack and wet and loose under my ribs and down into my hips. My head felt even worse … bile and matter and juices and oils, jellies and snots of thick green slime reeked and splattered out of me all over the black and white tiled floor’ . Or maybe you’ll make it to the protagonist’s dive into the literalised-metaphorical ocean which is ‘the liquid forever of history’ (‘I tumbled and rolled, pressed and pinwheeled through promises thoughts stories plans whispers lists lies tricks etc etc etc’ ). For me it was about halfway through, after Sanderson defeats Mr Nobody, and afterwards picks up his pillbox to discover that this individual (a creature in the real world) is actually a construct.
CONCENTRATION. Four milligrams … STYLE. EXTRAPOLATION. CONVICTION. FRIENDLY SMILE. POWERS OF PERSUASION. The little white pills inside each tub rattled. I bethought myself: but Neuromancer and The Matrix take the pains to rationalize the medium in which their sharks and enemy simulacra operate. The metaphorical world is one thing; the real world another; it distractingly nonsensical to talk as if a creature from the former can become materially embodied in the latter. But then I thought to myself: I know what this reminds me of: The Phantom Tollbooth. There’s that same childish belief that notional and real are aspects of one another; except that The Phantom Tollbooth is original, charming and winning, and Raw Shark Texts is second-hand, day-glo and deafening.