I am relatively new to PvPing in SWTOR so I can't really comment too much on how Juggernauts were prior to the latest update. Please correct me if I am wrong but to my understanding defense wasn't/isn't working properly and shield chance could be circumnavigated which caused tanks to get lit up by other classes prior to this?
Since I started playing I have yet to see a Tank dominate in any warzone they have been in. I have seen them survive the same but rank a little higher in damage and kills lately but isn't the purpose of the tank class to take a lot of punishment and deliver damage. Obviously damage that isn't at the same level as the DPS class but still some.
To me it seems like they have been tweaked enough so they are competitive in PvP.