Happy to follow up. I learn a lot on these forums, so perhaps someone can learn from my experience.
The rest of my system is currently:
Sources: Marantz SACD player and a Marantz TT (Jolida jD9 phono stage)
Preamp: Joule LA 150
SS set up: McCormack DNA-125 and Harbeth P3esr
Tube set up: Coincident Dynamo and Tekton M-Lore
The comparison of the M-Lore and the Harbeth P3 is certainly not apples-to-apples: a low efficiency $2,000 mini-monitor vs. a high efficiency $650 floor stander. I can't imagine a system/room in which they could both be used optimally. I would imagine the Harbeth C7 is the better comparator with the M-Lore.
I love the M-Lore and think it's the best bargain I've ever come across in audio. If I had a larger room that handled deeper bass better it would really shine. The P3s just fit so much better in my smaller space and have the clarity I was looking for. They just made me want to listen to music and stop thinking about tweaking my rig.
All the best,
Scott