It's just a personal thing. I feel like too many of the quests in the half-dozen-or-so hours I played of Lost Alpha were focused on going from point A to point B, going through a dialogue tree or two, and going back to point A, with very few--if any--threats in between (having to do with the static nature of the game's A-Life, something I hear will be improved before LA is finished, and with the lack of enemy encounters when going from place to place). It's not that dialogue-focused quests are BAD, per se--and they certainly did exist in Shadow of Chernobyl--but they aren't why I visit The Zone. Frankly, when I play a STALKER game, I prefer to solve my NPC-assigned problems with violence :P.

That's not my only issue. The experience-breaking bugs are certainly a big problem, and I expect those to be sorted out in the future. I'm not yet convinced that vehicles won't ruin the STALKER feeling of vulnerability, although at least they will solve the problem of levels that are boring to traverse over and over again. I was really, really disappointed with Lab X-18. I was disappointed with its laughing maniacal skeletons, its exposition-heavy cutscenes, and its need to explain exactly how certain mutants came to be. It didn't feel creepy to me, and certainly didn't channel the feeling of utter "wrongness" that I expect from STALKER's underground labs. I don't like that I was able to kill a bloodsucker with only 4 bullets. And while this is a minor complaint--and one shared by Clear Sky--I hate that your stamina won't regenerate unless you stand perfectly still, meaning that the already long treks across uneventful terrain are even longer.

None of this is meant to imply that I think LA is a bad game, and like I said, I'm waiting to try the finalized version before I form an "official" opinion. Those are just my initial impressions of what is currently an incomplete experience, as a STALKER fanboy :P