Terrell Owens has a habit of getting contentious with his quarterbacks and ex-quarterbacks. But on the field, he helps QBs to their best seasons. He's aided four different quarterbacks to 30+ TD seasons: Steve Young (1998), Jeff Garcia (2000 & 2001), Donovan McNabb (2004), and Tony Romo (2007). Only Young ever had a 30+ season without him.
I'd be wary of Terrell Owens, and I'd expect him to eventually say bad things about his quarterback. But on the field, he helps quarterbacks to career years.