Thank you for the response, and thanks for pointing me to the extensive discussion of subwoofers on Agon. Being a new member, I had not yet come across your thread "Do you think you need a subwoofer?" It looks like there's a lot of good info there on subs.
One thing I hoped my thread would uncover are specific <$2K subs that people found work well with the 10T's. Nobody has yet suggested such on this thread, but on your thread there seems to be a lot of discussion of particular subs. I suspect that getting a worthwhile improvement in my setup would require bigger and beefier subs than those available for <$2K. You apparently have settled on one of the Velodyne models and are happy with it.
For the time being I intend to take Jallen's advice and sit tight while I further study the pros and cons of subwoofing.
Your thread should be an enormous help.
Thanks again.