I haven't heard the venerable Dunleavy's, but I do have the the M4 Turbo S speakers and after rotating a dozen speakers through my system in the part few years, these are absolutely the best I have had in my room. I got the M4's as they are more room appropriate for me -- they are a bit less than a meter from the back wall and don't seem to be the least bit placement sensitive. To my ears in my room, they benefit greatly with sound absorption on the rear wall.
I was driving them with a Dennis Had EL84 amp and the sound was wonderful with a Don Sachs 6NS7 preamp, but I felt like the speakers were under controlled and lacked extension in the HF. I swapped a McCormack DNA .05 ss amp for the tube amp, and it is a match made in heaven. It has good LF extension, a sublime mid-range and outstanding HF extension, and a huge soundstage. The articulation of bass notes and drum beats is unrivaled compared to any speakers I have had. Frankly, I would not be as pleased with the M4's without the addition of a REL T7 subwoofer. The LF response added by the sub completely rounds out the sound. I am complete a devotee of Clayton's speakers, but feel they sound their best with a muscular amp and a subwoofer, however, the M3's may not benefit as much from a sub as do the leaner M4's. I talked to Clayton recently and am delighted to hear that his speakers sales are proceeding at a robust clip and I know why. I read a recent post elsewhere that referred to his modestly priced speakers as entry level speakers. I will grant they are in the sense of pricing, but in my 45 years as an audiophile, these are easily the best speakers I have owned and, OMG, I have had some very pricey speakers over the years.