I’ve had two sets of Mark Audio drivers. The Alpair 10P’s in a Pensil Cabinet and then some smaller mMar-kel70’s in a Fonken Cabinet built by David Dlugos.
I never could warm up to the 10P’s. I wanted to like them so bad too. I had the cabinets professionally produced and they were gorgeous, but the sound always struck me as a little “meh”. They weren’t as dynamic as my Omegas, not as efficient, and they were missing some of that single driver “immediacy” that I like so much. I sold them after 4 months.
The el70’s which were apparently a very limited run by Mark Fenlon built around 2009 are smaller RS5 sized drivers and they are really special. They have a beautiful tone to them and are just a joy to listen too. The only drawback to them for me is that they just don’t like to be played very loud, but if you play them in their sweet spot, they are just beautiful and have a wonderfully even balanced response.
Every driver sounds different and then different again depending upon the cabinet you put them in so take my comments with a grain of salt.