Deflection + Ricochet Skin made it so every other special attack bounced off its shell.
Retreat was very reliable.
Intercept is a bit lame (In PK) but you can work around with that.
The ability to take near to no damage is amazing. Especially if you need to get out of tight spaces.

In PK, I really only died to large groups who co-ordinated in different rooms. That, or I was lagged or trying to PK someone. There was some exceptions, but Armadillo is awesome with survivability and getting out of really tight situations.