I think it would be a fascinating spar - I would love to watch that and Carl would hold his own even at this early stage of his pro development.
Lets give the boy a time to develope before throwing him in a 10 rounder with an animal like Choi! :bbb
Who said anything about a 10 rounder - Choi's last fight was a scheduled 4 rounder - more like a sparring session/s with Choi - it would be great experience. I think Choi, a tough, experienced and relentless brawler (but very hittable) would be a great acid test for a talented upcoming boxer - especially behind closed doors during training.
http://www.theawl.com/2010/01/fight-night-with-hamilton-nolan-the-glorious-racism-of-boxing funny piece