My stance on this pick is that it's defensible. Not the pick I would have expected, but I think I see the reasoning. He has arguably the highest upside available at the position - Bender and maybe Chriss have comparable upside, but also lower floors IMO.
His physical tools are very good, and by most accounts his mental tools are as well. He's raw, but that's a profile that I don't mind taking a chance on. I do disagree with the Tyreke Evans comp mentioned by the draft coverage, though. Evans is a guy with a good handle who is capable of running an offense but has a hopelessly broken shot. Brown just has a decent handle and doesn't share that ability to create for others, but his tools are better - slightly bigger, a better athlete, and I think the shooting form is something you can work with.
Gonna have to be patient though. This board will likely be pretty ugly for his first year or so, because they're going to expect this kid to be an instant star and he's not that.