Of the three you picked, I have owned the JM twins and Ref.3a Dulcet. I currently still own and enjoy the Dulcet. IMHO, it is much more musically accurate than the JM speakers. I also owned a larger version of the Harbeths, the 7ES, and the tiny Dulcet speakers rule. There's something special about time and phase accurate speakers.
Most Engaging Monitor?
Thinking about moving to small stand mounted monitors. Narrowed it down to Harbeth P3ESR, Reference 3a Dulcet and Jean Marie Reynaud Twin. Looking for musical and engaging speakers that will pull me in to all night listening sessions and put a strain on my marriage and fatherly duties. Looking to buy used and match with my RWA Signature 30.2. I'll be playing cds and vinyl and listening to mostly rock, soul and acoustic from the '70s.