I am basically using two separate systems. I am matching my Pi Studio 2's with one of two SET Amps - Welbourne Laurels 300B's or Wavelength Gemini 45's. I love the SET tube sound with the Pi's. They match very well.

I also have a ribbon hybrid speaker (Newform Research R645) that I match with a Solid State Odyssey Stratos Amp.

Basically, I listen 75% of the time to the SET/Pi combo. However, when I need to get some "slam", I move over to the Newform/Stratos.

If I ever move to a much larger place, I would love to try out a larger Pi speaker like the Theater 4's. They are a little bit too imposing for me now.