Interesting thread. I was on a similar path not too long ago. I have had a pair of Merlin TSMs for several years. I started looking around for something better, or maybe just different. I actually quite like the speakers, but got the itch. The vast majority of the comments/suggestions I got on this and another forum was to keep the Merlins and upgrade some other piece of the pie. The only speakers that seemed to get some talk were the Josephs. But, new ones are out of my league and you don't see many used for sale, if at all. So, I consulted with Rich B at Signature Sound. I am presently driving my Merlins with a Billie integrated tube amp (original version). Rich suggested trying an integrated SS amp...the Belles Aria. Waiting for it to arrive.
In any case, good luck and share your experiences if you make changes.