I like him a lot, but unless its a deep league, he probably doesn't have a lot of trade value. Nobody's putting up much for rookies unless they've had a lot more hype than Miles has had.
He's had a couple pretty solid minor league seasons. I'd like to see him walk a little more, but there doesn't seem to be any indication that he can't maintain .315 or better average. Like most Rockies, he's a better play at Coors than on the road. If you can trade him, I'd wait until after a homestand.
Blessed are the cheesemakers.