A bit offtopic so I'll spoiler myself
IB only ever came in demand 1 time on this server (over SM) when you saw groups running proc group busters and couldn't afford to run any variation of SM because it got owned in seconds by the burst. Secondly you'll only see IB ran in serious groups if they are running some kind of weird 2nd string setup that absolutely needs an armor debuff. It's firmly in place as the worst tank on order just like BG is on destro, slightly more use not because it's better than BG, but because SM/knight combo isn't the end all be all like chosen/BO (but it's damn close).
I just finished reading all these BG balance discussions, and I am pretty much at the conclusion that we are gonna have to buff this class to godlike status before it ever sees use over the current implementation of BO/Chosen. Morale pumps are too strong, BO aoe snare is too good, BO damage is too good, Chosen (and knight) auras, superpunt, and misc utility are just too good etc...
I'd personally rather wait for client control to add completely new mechanics to BG like guard break for example to allow it to compete, or just wait for CH/BO nerfs.