Dark trooper isn't ganked, I own people all the time with blaster cannon in close range. Just keep moving/dodging, and time your shots instead of blasting away; with 5 shots per reload you have to make them count. 2 shot kills (1 if headshot) is plenty stopping power IMO.
I also prefer the Dark Trooper jump jets to the Jet Trooper jetpack in most situations, sure it has a long recharge time but this just means you have to choose your jumps more carefully, plus it gets you where you want to go faster. All too easy to get sniped while cruising around with jetpack