I'm still on the fence with this one, but these reviews are certainly swaying me. Whenever stealth was an option in a mission in the first game I absolutely loved every second of it, but for the rest of the game I really couldn't stand the missions with driving, shootouts, or just the scripted missions where you would fail immediately if you did one thing out of line. It sounds like the missions are more open-ended here, and that stealth is more viable, which is nice.
While I also thought the first game's story was shitty, it was mostly low-key and only ever got really cringeworthy during a few scenes, but from some of the footage I've seen of this one, like the E3 demo the characters and their designs seem insanely obnoxious and try-hard "hey kids aren't we cool?" which is really off putting.