Yesterday I was playing Crash Site on Wall st, and ended up in CQC with a Sniper, who was aiming down on one of the crash sites my team were occupying. I hadn't seen him at range because I'd just jumped in the window next to him. What followed was great fun, and involved strafing and meleeing and attempting to make enough space to use my shotgun. I Won the battle in the end with punches, but even though it only lasted a few seconds I have to say it was probably the best CQC I've been able to play; except maybe in Aliens vs Predator.
Bottom line, I think the higher health in comparison to games like CoD, and the 2-hit melee make for better CQC.