I purchased it over the weekend and will back up most of what KaOTic says. It's very linear, and I really do wish they'd kept some RPG elements. At the very least, I'd like to be able to go BACK to earlier settlements to sell/purchase items, and random encounters along the way would've been excellent. You could keep playing indefinitely, that way. Hopefully a mod will be released that will allow this, and add a ton more complexity like all the STALKER mods.
Checkpoint system - I prefer to quicksave. The checkpoint system would be GREAT if it saved more frequently so you had more load choices, so you can't have the situation coldmeat is stuck in where he has to replay a good 20 minutes just because he accidentally alerted a guard.
Stealth is not as well-implemented as I'd hoped. Would've really preferred a more developed stealth system.
Gameplay - Enjoyable! I really enjoy the concept of bullets also being currency, and I've really enjoyed the combat so far.
Overall, I think it's an excellent release, and if you want to play STALKER set on HL2 rails (very well-done rails), then pick this up. Besides, you're crawling around dark haunted fucking subway tunnels in post-Apocalyptic Moscow. Very fun.
