I'm using the two units in two separate setups:
Combined with the ATC SCM 50ASL Finest Fidelity, McIntosh D100 and a Auralic Aries it's an clearly significant improvement. The room opens wide, instruments are fixed at it's location and the bass get's more accuracy and definition. It's a serious improvement!
The second setup is a combination which shows every change of the equipment absolute dramatic: An Auralic Aries, a McIntosh D100 and a MalValve Headamp three plus Stax SR-007MKII (the 2.5er). It's with the AG500 like moving in a different world. It's no longer listening to recordings - it's so close to the perfect illusion. And it's with the AG500 indeed a huge and significant step forward.
I would say: Highly recommended.
My problem was: I had days when everything sounds wonderful. And the next hour, the next day it has been gone. With this experience it's clear to me: It depends on the quality of the power grid and that's absolute unpredictable. With the Power Inspired AG1500 and AG500 PWM it stay's constantly on the top level.
B Bohne 16 Feb 2015