K/D ratio is the thing I worry about. I can't stress over wins because there are 5 other players who affect that. Too many times in the past I've been stuck with wretched teammates and they waste a 30-5 (or something similar) effort on my part. Besides, it's a point of personal pride to me that I keep the K/D over 1. That's it. A modest goal, but one I like to stay above.
Campers are starting to annoy me, but I expect them. I just watch the killcam and pay them a little visit from the flank. Flashbang and semtex.
I've been getting scores of kills by watching for supply drops and taking out whole teams that run for it. That is more fun than a well oiled midget.
Run and gun still seems to be my best way of playing. I've tried playing sniper, but that's just not my style. I use a bit of sneak and peek when popping around corners, or heading into 'their side' of the board, but mostly, I'm running from cover to cover.