He's been a top 10 hitter in all of AAA, is young enough for the league, and doesn't have some of the red flags of hitters above him (age, uber-high BABIPs, big K's, etc).
Biggest concern is obviously if he can stay at catcher, and if so, how do the cubs transition between him and Montero (who's been getting on base enough and has well regarded d).
Will be an interesting trade to track.