By far the best looking Tomb Raider so far and Lara certainly looks her best. Eidos have made the most of the hi-def graphics the PS3 allows them, and the environments look stunningly beautiful and realistic. The PS3 has also allowed for much bigger areas to explore, giving you a real sense of the massive scale of the locations you find yourself in.
There's much more freedom of movement too, but without the need for silly gimmicks (as in some previous versions). Instead, Lara's existing abilities have just been expanded, so that she can utilise her surroundings more (and her grappling hook), and in a far more naturalistic way than before, so you get more of a sense of controlling a real person, rather then a bunch of pixels. There are still a few restrictions, locations where you think she should be able to get to, but can't, but what it lacks in freedom it more than makes up for in fun. But Tomb Raider is not a sandbox game, it's essentially a puzzle game, and so restrictions are necessary to allow the puzzles to work logically.
The puzzles and challenges themselves are also ingenious, some of which are so clever that you feel a real sense of achievement once you figure out what to do. You can tell a lot of effort went in to coming up with some of the more complex puzzles.
Overall, Eidos haven't tried to re-invent the wheel with this instalment, simply taking the strengths from the previous two (and removing the weaknesses, like the quick-time cutscenes) and improving on them, whilst vastly expanding the canvass thanks to the extra power of the PS3. This is possibly the most well-rounded of the recent TRs, and I hope the next chapter doesn't stray too far from this winning formula. Plus, I don't know why anyone would say this game is too short, because it's easily as long as, if not longer, than previous TRs.
If you haven't played a Tomb Raider game since PS1 days, because they started to get a bit rubbish, then you won't be disappointed (and if you've got a PS2, then you have to buy TR: Anniversary!). You get that real sense of isolation that you got in the originals, that you're out there on your own, hundreds of miles from civilisation without anyone to help or rescue you. The most recent TRs, since Legend, are easily as good as, if not better, than the originals and I really hope they continue in the same vein.