I am speaking in terms of level design, not the controls. Have you played the SP campaign of R6V2? While in the first game the enemies were somewhat realistically placed, in R6V2, you can encounter like a thousand baddies in each small building. Sometimes there are a hundered baddies scattered in a single corridor. What the hell are they doing? Having a conference? Also, why aren't they together? What is the point of a hundred terrorists in groups of ten taking separate positions in the same hall??? With each group just enough apart for them not to hear the group calling for help, but still close enough to have stood together. Obviously, I am exaggerating, but you know what I mean.
And why is there a boss fight? WTF?
And then there was the ridiculous achivement crap, that totally reeked of consolitis. I don't mind achievements as long as they don't disturb the game ala hl2:ep2, but they are really poorly implemented in R6V2, and feel totally out of place considering it is a tactical game.
For example, you have different achivement trees that rewards various styles of play. These trees include long range shooting, demolition skills, close encounter kills etc. Now that's all fine, but the rewards are locked weapons and equipment which are somewhat essential.
The worst of it is that plenty of weapons can only be unlocked once you reach a higher level in a certain style of play. Now when one of those achivement trees constantly asks you to get extremely close range kills, I get ticked off. It has no place in a tactical shooter.
At one point, I really wanted the equipment that was locked behind the close range kills tree, and I ended up running around like a mad man with a desert eagle, hoping to clear the entire level by blowing up each terrorist's face while standing right next to them. Of course that's when I really started dying a lot, and hating the game.
Imagine if that happened in real life. What if there was a hostage situation at the UN, and the SAS started running up to the bewildered terrorists armed with baseball bats so that they could get extremely close range kills in order to "unlock" better equipment.
The whole mechanics of the achivement stuff was just totally out of place.
edit:
Admittedly, I played the game again with friends in co-op mode. I have to admit, it was really badass.
Just wasn't a proper SP experience.