All I can say that I played the first one, the original S.T.A.L.K.E.R., and it was a gem of a game. The other games who followed in the series weren't as successful and were riddled with bugs and problems. Even though there were technological advancements in them, they didn't "feel" like the original game.

So, for this, I am very happy that they are finally deciding to release S.T.A.L.K.E.R. 2, and I will play the "heck" out of it when it releases.