Depends. Titans can be good. The Striker's Fist of Havoc is a hard counter to a Bladedancer Hunter and Defender Titan. If you can learn how to use shoulder charge, you will get some awesome kills with it.
Defenders need to use their Ward of Dawn and Force Barrier buff to stay in the bubble and beat down opponents. You are nearly invincible with that combo inside the shield. Just beware of Nova Bomb, Fist of Havoc and Gunslinger. (Defender is a weaker PVP subclass, but still viable with magnetic grenades)
English
-
If you can use suppressor grenades and high jump correctly, you will wreck as defender and stop a lot of supers from taking down the bubble.