I watched a fair amount of Texas games this year, mainly to scout Damion James, so I saw quite a bit of Bradley.
He was interesting to watch in that he had two very polished assets, his defense and pull-up J, and the rest of his game was completely blank. He had a solid handle but he didn't know what to do with it, he had no drive and dish game, he had no idea what to do when he got to the rim and he often just stood around without the ball.
In Boston, he'll be able to concentrate on what he already does well initially and hopefully be able to add additional skills slowly.
He's not all that unlike Russell Westbrook. Possessing virtually identical physical tools, their games aren't that much different either (though Bradley's more of a shooter and Westbrook's more of a scrapper). Not sure if Bradley can match Westbrook's ability to dramatically improve his game every year, but the raw materials are there.