I had Harbeth M-40.1's about 10 years ago. For no good reason, other than audionervosa (foolishness) I sold my 40.1's and replaced them with a dealer demo pair of Daedalus Ulysses (without hearing them). The Daedalus required extensive break-in, but eventually loosened up. The Daedalus Ulysses were good speakers and had furniture quality cabinets, but they just didn't do it for me like the 40.1's. I sold the Daedalus Ulysses after about 18 months, then tried Harbeth SHL5's for a bout a years and now am back with 40.1's, with zero interest in trying anything else.
If you want full bodied / full range, organic and natural sounding speakers, I would try to find a used pair of Harbeth 40.2's. Your 10' x 15' room might be too small for the 40.1's as they are a bit bass heavy.