I hadn't read the book before (and not sure that I am in the right frame of mind to read it now that I have seen the film), so I just saw the movie as a member of the non-Ballard reading class (though I did love "Crash" in it's own demented way).
The film is really really out of mainstream, so I think that the people to whom it appeals may not necessarily be the ones reviewing it. I thought that Tom and Luke's performances were outstanding (as well as Sienna Miller's) so on that note, I would recommend seeing it. Jeremy Irons was good though with his smock he reminded me of his "Dead Ringers" character.
The only performance that struck a slightly off note, was James Purefoy - he seems to specialise in nasty upper class characters and though he was essentially comic relief, I thought he was hamming it up a tiny bit at certain times (I could almost see him smirking).
I forgot to mention how cool Clint Mansell's score was and the wonderful, wonderful way he appropriated everyone's favourite 70s Swedish pop phenomenon (SOS is still in my head).
For Frenchy - innocuous as any other somewhat rabid fan. But that .. an excited fan. Even if she weren't (and I am NOT suggesting this) I personally don't support the vitriol directed against anyone Tom might be linked with as it is slut shaming of the worst kind.
Finally: I didn't want to mention this last night as the event was still on but the afterparty was held at .. The Royal British Institute of Architecture! I thought that was extremely clever ..