I have heard them with Ayre, Sim, TacT and Spectron and they were all quite good. Although it appears as your amplifier is the weak link in your system, I am a bit surprised as to your comments regarding the "sweet spot".
If you care to email me your phone number, I would be happy to walk you through my version of how the speakers should be setup and placed.
If you care to email me your phone number, I would be happy to walk you through my version of how the speakers should be setup and placed.

