I day sail and race local. I have been considering taking mine down to Annapolis for their double handed distance regatta in the fall (Sort of a pre-Olympic regatta back when there was going to be a coed DH Olympic class). I think it is a perfect double handed boat and while we have done very well double handed in our little pond, I'm sure I'll get my butt kicked down in Annapolis, but its worth at try.I would say that j/100 sales are still strong even with J/9 model taking orders. A 2005 j100 with sprit just sold for 100k in RI. Quite a few people joined the owners group on FB but would encourage anyone else with one to sign up. My guess is most are being used for day sailing and local fleet racing. It would be nice to gather up enough interest from J100 owners to have a presence at a future national regatta. Not necessarily to have their own start but at least a few boats on the line. But I guess if a boats as pleasant to sail as the J100, even your local harbor or venue is plenty fun enough.
There are two J/100s that raced in the Annapolis Wednesday night series and one of them attempted the DH distance race. But they haven't faired very well. Finishing last would have been an improvement.