I've been using an Audio Note P2 SE myself for the past few years along with an Audio Note M1 preamp. This is essentially the same combination found in the Audio Note Soro integrated amp. I haven't compared the M1 to the M2, but the M2 is reputed to have a more refined sound.
You're right regarding the effect a good preamp will have with the P2 SE. More bass and dynamics. The P2 SE though by itself is more transparent sounding in my experience.
What to do? Personally, I would go for the M2. The Soro integrated, good as it is, does not offer the flexability of a separates as far as upgrading either the amp or preamp. Plus you already have the P2 SE. Perhaps the solution is to try out both the M1 and M2 with your amp, if possible, and see which one you like the best. I'd be interested in the results of that comparison as I have my eye on the M2 as a possible future upgrade.
Good luck and let us know what you decide upon.
You're right regarding the effect a good preamp will have with the P2 SE. More bass and dynamics. The P2 SE though by itself is more transparent sounding in my experience.
What to do? Personally, I would go for the M2. The Soro integrated, good as it is, does not offer the flexability of a separates as far as upgrading either the amp or preamp. Plus you already have the P2 SE. Perhaps the solution is to try out both the M1 and M2 with your amp, if possible, and see which one you like the best. I'd be interested in the results of that comparison as I have my eye on the M2 as a possible future upgrade.
Good luck and let us know what you decide upon.