Just a recap on my trip:

Made the connection pretty easily in CLT (37 min), but it helped that my outgoing flight was delayed a bit. No luggage to check, so no worries there.

15 minutes sounds about right, based on my experience (12 minutes for me from E28->B10, and a brisk walk, but no running).

The one thing that could have caused problems is that retrieval of planeside valet bags was incredibly slow - the 12 minute cushion I had because the originating flight was early was wiped out because of waiting for the bags (one of the pilots was a little surprised that the bags were taking this long to retrieve). While it wouldn't cause an issue even if the departing flight was on time, if the originating flight was on time or a couple minutes late, I probably would have been stuck in CLT.

Like with many things, this really comes down to a "what are the stakes if you miss the flight" issue - the flights the next day were $150-200 higher, and earlier flights would have cost me about the same amount of money in vacation time used, so this was worth it to me. As always, YMMV.