Fortunately I have two GC's within easy reach and I have to say that the Gibson's I've experienced have been wonderful! One day I played a gorgeous SJ-200TV that spoke volumes to me (until I looked at the price tag! ) and then just the other day, I enjoyed A/B comparing two "identical" J-45 models side-by-side. Of course, they weren't "identical", but they both sounded and played great.
Have you played one of the J15s in your visits to GC?
Yes ... I've played the J-15, the J-35, then J-45, and the SJ-200 at various times. I was impressed with them all. My only complaint about Gibson is that I prefer a slightly wider nut. I like 1.75 and Gibsons are 1.72-ish.