I have three sets of gear for my shadow. One full tank for huttball, one unlimited power one for 31 0 10 / 2 31 8 and one with a tad less power and crit for when i go balance spec. When I carry the ball in full expertise/survivor gear adjusted for a bit of defence, there are powertechs on TOFN that kill me in 5 seconds tops, with a 5k railshot through deflection.
To answer the question, Shadow tanks are by far the squishiest tanks in PVP at this point in time. Our only defensive ability has been broken for months and nobody cares. I got 4k railshot thru resilience today and that my friends has a trolololol label attached to it.
You're doing it wrong.
Get pocket healed and it will take a very skilled dps to take you down.
Uhmm ... 'get a pocket healer' ... I am sorry but with a pocket healer it will take a very skilled dps to take you down in any class.