I loved most of the SGW's, but I enjoy this one the most. It's fun to play, and there aren't many fun sniper games like this one. I'd say stealth need a bit of fixing, it's pretty buggy. Also NPC dialogues get very repetitive, and there is only one voice actor for them. But for the discounter price, you can't really complain. It's a good game.
I've been binge playing all the SGW's lately because they've been practically free on GOG. I must say that this is my today's favorite sniper game to casually play on my free time. It's a nice break from all the blurry and barely running games on unreal engine. This game has beautiful visuals, a cool enough campaign to have some fun, and nice sniping techniques. What else do you need ? I wonder what's cooking for the next SGW :)