Jedi Guardian, Focus spec, level 47; T7's Damage reduction from armor is at 24% (28% with buff from Flameguard). Armor is all custom droid armor with Commando armor mods. To compare my own DR is 27% in Shi-choo form and 40% in Soresu stance. Something is wrong here.
If I don't turn off Stimulus applicator (=Taunt) and Flaregun (=AoE Taunt) T7 dies faster than i can kill the enemies. Luckily, comp-tanks have good threat generation without the taunts, 1 good thing about them atleast.
You shouldn't NEED purple FP/Ops gear to make a comp-tank viable, you should be able to use them efficiently while you level 30-50.