XA25 is a great amp.
I just did an extensive AB with my LTA ultralinear
my buddies and I generally preferred the xa25 mostly due to increased bass extension. both are amazing and have a very different signature. The LTA has this crisp detailed image while the Pass is more relaxed and warm sounding. I know, it should be the other way around with tubes but that is not what we all heard. My favorite analogy: The pass labs is a well colored in shrinky dink, done very well. the LTA is what it looks like after being nuked. more detail but smaller.... make any sense??? The pass sounds bigger and warmer..... LTA tight detailed, pin point image.
They are both great and just different flavors!
good stuff.
(Wilson speakers used, Lampi DAC) -steve