I'm using a PS Audio HCA 2 with the Cullen mods and I love it.
I auditioned a variety of amps in my home - a high powered ARC tube amp and a Pass Class A amp at the same time I had the PS Audio. I think I may have liked the Pass amp about as much as the PS Audio, but I'm inclined to keep my gear turned on all the time I didn't think I'd like the extra heat and energy usage.
Time and innovation march forward so I'm sure there are others that are better, but I'm not feeling any urge to upgrade at this point.
I auditioned a variety of amps in my home - a high powered ARC tube amp and a Pass Class A amp at the same time I had the PS Audio. I think I may have liked the Pass amp about as much as the PS Audio, but I'm inclined to keep my gear turned on all the time I didn't think I'd like the extra heat and energy usage.
Time and innovation march forward so I'm sure there are others that are better, but I'm not feeling any urge to upgrade at this point.