I called up an overall #1 pick (SP) out of college from Low-A to AAA after his draft year because he had the ratings to pitch at AAA. I figured he'd get regular starts, have better coaching than in Hi-A or AA and thus would continue to progress. He only gained 5 overall points and roughly the same across the board for splits, pitches, etc. He threw up a 6.38 ERA and was 6-17 with right at 70 stam/70 control/60 splits/80 velo/60 GBFB/and 70/60/50/40/30 pitches. I left him at AAA the following season, paid out the wazoo for a good pitching coach and he's shown a little better improvement, but I really believe bringing him up early stunted his growth.
Not sure how to post a link, but it's Dillon Malone on my Honolulu team. He's at the ML level now because I brought him up in September of this season.