You both are apparently not reading any of the pre release articles or watched any of the dev commentaries or trailers? This game is non-linear open world, and has a plethora of customizing of weapons, both of which the first two didn’t have.
No, I don't care about watching game videos. I'm not into watching other people play, regardless if the game is out or not. I don't listen to boring commentaries nor watch trailers. Consider me old fashioned, but if a game offers a demo, then I'll try it out and I can better derive an opinion about the game from that method. Otherwise, I might read up on an article or two of a game that interests me to see if it's something I should follow and look into getting.
The first two games weren't that impressive aside from the graphics side of things. I didn't care much for them. This new one might be good, might be bad....perhaps mediocre....
STALKER added in weapon customization for Clear Sky - didn't make the game much better. I still enjoyed it, but just because you can customize weapons doesn't mean it's good.
I got to customize weapons in Tomb Raider (2013) - didn't make the game any better (in fact, the game was kinda shitty - Lara came off as a cross of the Terminator, John Wick and Rambo. Can't be killed, falls from great heights over and over again. She shoots and melees people like John Wick and handles a bow like Rambo from First Blood: Part 2)
I don't think the atmosphere was much different than the felling you got from STALKER: CoP, in Metro games - kinda creepy, but not as well done as CoP.
I don't feel the new game adds anything new to what is already out there. Maybe someday, a year or three after it releases I might pick up a copy when it's cheap, but based off the first two games, I'm don't feel the need to get it right now, regardless of what digital site sells it. If you want to enjoy the game, go for it. Doesn't hurt my feelings.