if you plan on being in Soresu form I'd use a shield for sure. Other than that, defense, shield, and absorb all do something...maybe not as much as you'd like, but they all make you harder to kill edit: are they worth trading dmg for more survivability? that will depend on your play preference

something like: http://www.sithspecs.com/sith-warrior-juggernaut/swtor-sith-warrior-juggernaut-build-hybrid-pvp-spec/ might work for you Unstoppable is very nice for Huttball Invincible (Immortal tree) and Deafening Defense (Veng) make you harder to kill The Veng tree also adds some dmg, so if you wanted more survivability I'd stop Veng at Deafening Defense and put the rest in Immortal (for things like Sonic Barrier and Shield Specialization).

...and once pvp'ing with it, I have a hard time building any spec without Force Grip. While it is doing dmg and stunning your opponent you are doing additional dmg with abilities and loading up your smash. Oh and in addition to missing Dark Resonance, you'll miss Force Crush. Force Crush is very nice as a DoT, slow, and a builder of Shockwave. Without Force Crush you may have some Smashes in your rotation without Shockwave.

This is essentially the build i've been running in pvp except I took Sonic Barrier (although not sure how useful it is) and I stay in Soresu form (so no Overpower). Using full tanking BM gear I'm difficult to kill and can do decent aoe/burst dmg. It won't get you a lot of mvp votes, but on a good match I got something like: (voidstart - full duration) 280k dmg (3rd) 175k protection (1st by a wide margin) 50k healing, 14 medals I've tried a number of different Immortal hybrids and this is my favorite. I'm currently building up some damage gear to see how well the build works with more dps gear and less tanking gear. edit: for example I tried Immortal/Veng hybrid and survivability may have been better but i didn't seem to do much dmg (especially burst dmg). Immortal/Rage is the only one I've found that has both dmg and survivability. I did really like Deafening Defense and Unstoppable (Huttball) though.

I can't comment on pve tanking, but I've been using essentially this spec in pvp for a while now. Using full tanking BM gear I'm difficult to kill and can do decent aoe/burst dmg. It won't get you a lot of mvp votes, but on a good match I got something like: (voidstart - full duration) 280k dmg (3rd) 175k protection (1st by a wide margin) 50k healing, 14 medals edit: and of course something that won't show up on the stats: i take a lot more abuse before dying

Since it was civil war, total dmg doesn't matter that much. Just have both teams capture zero turrets and fight until everyone is above 1mil, then start capturing. That being said, the dmg per second is very good at 837. On my battlemaster shadow I get about 400 dps on a good match, which results in about 350k dmg. So 800 dps would be about 700k dmg on a normal length match (I'm guessing there was a lot of 1-2 and then 2-1 turrets or even a 1-1 with one being fought over - making this match last longer than usual). This is still very good dmg. edit: also i guess having zero deaths and assuming a constant fight, would mean a much higher uptime than normal - also adding to the damage total.

I use all stalker with the survivor shield. Works very well. Probably could further optimize, but mine is the lazy man's gearing choice. With combat logs and target dummies coming soon, you'll know a lot better. I'd wait until then to optimize.

this ^ or something similar

as others have pointed out...this isn't true. It was hard to continue reading after that (which was your first comparison) since it was obvious you were biased. Tank assassins have low burst, decent to good sustained dps (in dps gear) and decent to good survivabilty - kind of a jack of all trades. That being said, tank version of assassin/shadow is very strong overall and may need adjustment - although it still remains to be seen if a jack-of-all trades will be good in rated matches which can be dominated by specialists (i.e. bring 1 high survivability tank and 1 top dps instead of two tank-assassins) Personally, I'd like to play infiltration (dps) but survivability of that spec may be the worst in the game.

definitely some oddities in the gear For Shadow, most of the champ to BM trade power (from champ) for surge and crit (BM), but a couple of the pieces trade the other way around... Then they nerfed surge and many people believe it made the champ gear actually better than the BM gear.

I agree with the OP. There are too many skills and not enough reasons to use your brain in SWTOR pvp. I wouldn't call it "mindless piano" playing, but it's too close to that for my liking.

this (most likely)

I hope so...then I can go back to infiltration. I'd go back now but kinetic is too damn good

I think the resolve system is very good. It is a transparent way to limit how much you can be cc'd. The problem is there are too many mez's, stuns, and roots in the game in the first place so that we are always waiting for resolve to help. As mentioned, it isn't much fun to lose control of your character...sitting there waiting for a stun or mez to wear off. It should happen less frequently, but I don't think it is resolve that should make it less frequent - there should be fewer stuns, mez's, roots. A possible solution off the top of my head... add a chance for the stun/mez/root to miss (or be dodged or whatever).

If you go to the 'Classes' forum for Shadow you can find a lot of information about pvping as a Shadow (spec, gear, etc.) short answer: A lot of people believe tanking stats are not very good in pvp longer info: I've done Infiltration and Kinetic (31/0/10 - current). I use all stalker gear with a shield offhand. My dps is slightly lower than when I was Inf (burst significantly lower) but my survivability is much higher. If you used all survival gear, my guess is your dps would go way down and your survivability would go up slightly. I have BM stalker and champ survival, but haven't used a full survival set for pvp. Another thing some people do is get both sets and take mods out of the stalker and put in the survival gear (so you get the survival set bonuses, with the stalker dps)