I have had six different Pass Class A amps in my system. My favorite is my current XA160.5. I have not heard amps from other companies in my own system, but I have heard a few amps in friends' systems and at various dealerships. I have been very impressed with the Spectral mono blocks and to a lesser extant with the AYRE monos. I'm sorry I don't have more experience with different amps in my own system to give you a better opinion.
Amps in the same class as Pass XA.5 series
I've read a lot of posts saying that the Pass XA.5 is the best amp the poster has heard. What are some other amps that are in the same league?