No point in fussing around - if you liked the first outing, Stalker Shadow of Chernobyl (SOC), then you will like this, and it's worth getting. BUT, patch it straight away*
If on the other hand you prefer Call of Duty, or Doom, or those sort of very linear shooters, then avoid this like the plague - you will hate it!
* Patch it to 1.5.04 - only two patches - which gets rid of the stash management issue + seems more stable. For those who, understandibly, gave up at 1.5.01 - now might be a good time to give it another go!
This is a return to form for GCC - and not always in a good way, e.g. the essential patches, both invalidating the previous version's saved games! But on the BIG plus side, GSC care enough to turn out patches, and support a very active modding community.
More on the plus side - the graphics have evolved well and look lovely, and the weather, fog, evening mists, rain (of course), sun etc all work very well - going through the Red Forest at night in a thunderstorm, after fighting off a pack of dogs, was all amazingly intense. The sound-scape is excellent too and really works well. It's all very immersive - just what you'd expect and want.
Naturally there are issues/irritants - the stash management was a total farce - until patch 1.5.04 arrived - and it's now OK. The inventory is now 100% opaque, so you can't really use it on the move let alone in the middle of a fight, and it's tricky to easily compare the health of backpack items.
More... the NPC are still immovable, and displace you like bulldozers as they move. When you die (and you will!) the 'quick load' key doesn't work, forcing you through the main-menu 'load game' rigmarole.
And... the radiation detector is almost silent, which means... well you can work that one out, right!? And... you can't sleep, to hit the day/night cycle you want; you can't jump/run in even the shallowest water; some of the story event don't trigger if you don't follow the 'correct' path - so you have to loop back and find the invisible line to cross; you can't (seemingly) sell NPC's guns or ammo; one of my save games crashed the game every time I tried to load it - causing me to go back to a previous save (top tip - keep several saves!)
So I'm having a right old whinge, yet still gave it 4 stars?
Well it achieves the immersive trick of putting you a 'real space', leaving you to amble around the zone 'just having a nose' and bumping in to things - which is a hoot. And Entering the Forester's camp at night with lightning flashing all around was worth the money alone.
Worth noting though - there don't seem to be any significant underground missions - which seems like a real mistake to me, and I'm not convinced this is actually a better game than Stalker SOC - but if you liked the first game, get this one. Similarly, if you like this one, get SoC, patch it and apply the 'Oblivion Lost' mod - it's free and really v good - and similarly 'Priboi Story'!
Using both old and new parts of the Zone strangely delights, as the old areas are familiar yet different, and there's enough ammo lying around - you just have to rummage a bit.
So if you like games that you can take your own time with and that, despite all attempts to frustrate, do reward the time it takes to 'get into it' then buy it - once again GSC have produced very distinctive and genuinely immersive game.