I only fire from hip in desperate situations in close combat.
I don't for the entire reason that you can continue to run at a decent speed and maintain decent accuracy if you do short bursts. If they haven't seen you, or don't specifically need to aim for a small target (like a head over a box) it makes a lot of sense to do it. The fact it takes a short time to actually switch to aimed mode as well also aids you over someone who always aims down sights.
If you aim down sights you walk at a very slow pace thus losing a large amount of mobility and become a basically stationary target with restricted field of view, even with holo sights. I find unless I need magnification or to hit a small target, or a longer range target.
It's highly situational, but don't discount firing from the hip. At medium ranges it's quite effective. But then, even at short range I sometimes use sights, it depends on what you need to do... for example if you reckon you've got a decent headshot even at short range, in a face off... sometimes down the sights is the right choice.
TDM really helped me improve my CQ Infantry gameplay incidentally. Spawn death is a frustation, but I'm now quite regularly called a cheater which is nice
