you might find that using tubes with AP will open the midrange out greatly, and add a lot of warmth through the mid bass. I originally auditioned the virgos with bel canto, and found a thinness in the mid, just how you describe, although it was very detailed.Same went for Classé amps. Adding my unisis brought out a cohesion and far better balance, and the good news is AP`s are easy to drive. I know of someone who is using an 8w minimax valve amp with a pair of avantis, and doesn`t wish for more.As a guideline, my 30w push pull drives my paduas to earsplitting levels when the need arises, but as i listen at relativly low volume (7 o`clock on the volume), i need something with a balanced sound at low volumes. I found tubes to do this with aplomb, so i think you will be happy.
let us all know how you get on m8.