Weeeeeeelll, I got my new 6870 black edition this morning and used my voucher to download this from Steam, which took most of the afternoon.
I've just played a couple of hours worth and first things first the characters can be a bit DNF but overall the graphics are very good and with everything maxed it looks sweet and runs a dream @ 1920x1200.
I set the difficulty to medium, and it actually felt like hard mode to begin with, I died very quickly numerous times on the first groups of enemies - I find the stealth cover and other controls a bit clunky and its rather annoying that when you crouch you have to press the same key again to uncrouch - basically its just going to take me some getting used to as I'm not a 'stealth' person. It doesn't help being given a crap rifle with only 6 tranq. shots that don't seem to work very well. My first decision was to try and not hurt anyone and be stealthy which went out of the window straight away given these facts. It took too long and I was getting shot too much, so I'm progressing much faster just by shooting seven shades out of everyone now
Overall I think I'm going to hop in and out of this one. The cutscenes, etc make it enjoyable but given the mission lengths it seems like you need to devote some time to really getting into it, but I find some of the objectives and instructions a bit vague, like rescuing hostages that I couldn't even find! But overall its good fun and I quickly killed a couple of hours without realising it, not that I've got very far
