I think Bradley is a bit better than TA (better at chasing his man through screens, ball pressure and biting on upfakes) however, TA is a more versatile defender. I dont think Bradley can guard a whole lot of 3s, and I believe the versatility in the positions you can guard (2 positions vs 3) is a very important aspect of defense, so by that virtue, TA is a better option.
I really like TA but I don't miss his bonehead plays and bad shot selection.