I am very grateful for all the suggestions and expertise. I guess by way of clarification: I'm more of a music lover and vinylholic than an audiophile. At 70, and on a fixed income now, I'm hoping to make one more adjustment to the rig... and that would definitely be speakers. While the MKs have a generous soundstage, the depth isn't there (again, a 12x12, dual purpose, living/listening room). Imaging isn't as crisp as I'd like, and then there is the bass which, while fairly articulate and natural, isn't very present at all.
Thoughts on ELAC (which schurbert mentioned... model?), B&W 606 s2, SVS Prime, others? I have the ProAcs on my list of auditions (gotta brave 50 miles of ATL traffic to meet a new dealer), but finding another $500-1K is a real stretch. So I continue to collect data here (and from my local, true audiophile buds) in what will be a lengthy process.
Again, my gratitude to all. Happy listening!