Where are you valuing him compared to the Keenan Allens and Justin Hunters of the world?
I don't think Hunter is a perfect prospect, but I would still take him ahead of Brown. He is an atypical package, but his height, speed, and crazy leaping ability give him a pretty high ceiling IMO despite his glaring flaws. I think he is capable of having individual seasons like the one Sidney Rice had with Favre back in the day.
I would probably take Brown ahead of Allen right this minute. Brown has already shown a lot of the signs that you can only hope for from Allen.