Sadly, there are very few active/up-to-date places to find information like the OP is seeking. As can be seen in this thread, people are typically biased in one way or another.
For awhile during the beta, there were some very thorough mathematical threads on the official tank role forums comparing expected sustained damage for each tank, and those helped drive a lot of the late-beta balance decisions. I haven't seen a similar comparison done in some time, likely because most people aren't familiar with the mechanical nuances of each tank.
Personally, I think the OP should try each tank and figure out which playstyle appeals to him or her. Whatever the state of balance might be right now has little bearing on what it will be in 4.2, 4.3, or any other patch point. Your ability to keep your head on straight night in and night out is influenced heavily by your enjoyment of the class, and is far more important than minor survivability deltas between each tank spec.