Level 50 Shieldtech here. I've got around 20.5k health right now, mostly PvE gear. I average around 200k+ damage, 50k Protection, 30k Healing (thanks medpacs lol), and 9 medals each WF I run. With my guildmate, an Operative healer (level 37), I've successfully tanked an entire team of 8 people for almost 2 minutes. (this was on Civil War holding a point) Huttball has become a joke if I get the ball as I can currently tank their entire team to the endzone unless they are well-geared and coordinated.
Powertechs bad in PvP? Far from it.
PS: Just got my new Champion Supercommando Pistol today so that should add onto those numbers a little as well.