Bradley doesn't have size to defend wing players properly, so it doesn't make sense to compare him to guys like Bowen. Bowen was a great defender of 1s, 2s, 3s and some 4s. Bradley is limited to 1s and some 2s.
I am very impressed by Bradley's defense though. He gets in the ball-handlers grill as few other players in the league right now, if any. His on-the-ball defense is impressive, he has active hands, he slides well through screens, doesn't slack on his stance off-the-ball... sometimes he overcommits a bit, but I think with some experience he can be the best
He's a nightmare matchup for those weak ball-handling guards some teams trout in their second unit.
Offensively, I think he'll be good enough of a jump-shooter.
Bradley reminds me of a Brian Shaw. He'd be a great fit next to a Magic Johnson, a Larry Bird, a LeBron James, a Kobe Bryant.