Just completed this, thoughts below:
+Visually impressive in terms of the outdoors environment, I've always like the Chrome engines
+Decent performance 75+ fps
+Good balance of sniping, stealth and combat (I was worried it would be over stealthy but it lets you do silent kills etc)
+Rewarding kills (gratuitous slo-mo leaves you wanting to shout "BOOM, HEADSHOT!")
+Nice atmosphere in places, sneaking around with tips from your teammate
+Seeing the action from different perspectives is nice
+I quite liked the fact that the missions aren't overlong, generally around 10-20mins each (min was about 4mins, max about 30).
-A bit short overall though, only lasted about 5hrs total (game said 4h17 but obviously I reloaded a few times)
-Weird glitch on one mission where I reached a checkpoint but enemies would be on instant 100% alert as soon as I got in their LOS (even in crawl mode), had to load an earlier save
-Environments are a bit repetitive
-Really bizarre random story twist towards the end
-Close up texture graphics are nothing to write home about, especially in buildings
-FOV is too low
-A few annoying sections playing support where you can't continue until you eliminate certain enemies, but you have no idea where they are so have to spend a couple of minutes randomly scanning (why aren't your teammates spotting for you instead of just asking you to help them?)
-Terrible abrupt ending (it makes MOHAA look good), it definitely looks rushed/incomplete as you even get given a new objective to extract and then it just ends :/
All in all I'm pretty pleased with it given the mediocre reviews it received; unlike Sniper Elite I found it fun to play.