Bryston or Pass Labs

I know this is a old thread but I'm finding myself with a loaner 4b3 which I like very much but I also like what I read about Pass and am contemplating buying on approval from Reno or finding a used unit.  I'll note here that if you can go to the X150.8 that amp actually competes price wise with the 4b3.  The Pass products are generally grossly underrated power wise and perform 25-35% higher than their stated output.  So while the x150.8 is not as underpowered as you think it might be in comparison to the 4b3.  The 4b3 is FAR FAR more musical to me than the "squared" series, much more delicate upper midrange and highs, beautifully detailed but not etched.  It still is a little lacking in the presence department but only slightly and my suspicion is that's where the Pass will exceed the Bryston.  The Bryston is however an exceedingly "fast" amp without being etched and is also totally dual mono with two stacked transformers (one for each channel).  The build quality is astonishing and the thing can just put out a huge amount of power with no compression.  I can easily listen to 110 db peaks on large orchestra recordings on the Bryston with no compression or odd things going on at all so I am impressed.  Any further thoughts from anyone are welcome.  My front end is largely digital (Bryston BDP-1) using Audirvana and a tubed Aesthetix Janus preamp with Thiel 2.4s.

I received a Pass x150.8 yesterday and I have to say these two amplifiers are entirely different.  The Pass is very liquid, three dimensional and palpable whereas the Bryston is very analytical and revealing.  While the Pass also retrieves a HUGE amount of detail from recordings there are some that will find the Bryston preferable.  Since I'm only one day into the audition of the Pass I haven't quite decided yet but for people who believe all SS amps sound the same as long as they are high current and have plenty of power reserves compare these two because there's a huge difference.  I would say initially that I favor the Pass but the problem I'm having with the Pass is that on orchestral music and particularly loud orchestral swells the Bryston is simply more accurate and conveys more information...i.e. its more analytical whereas on the Pass I get a bit of a homogenized sounds on orchestral peaks.  I DO find the Pass amp far less fatiguing when listening to loud orchestral music.  One interesting tidbit of my experience is that the Pass idles at a far higher electrical draw than the Bryston even though they're both Class A up to 10 watts for the Bryston and 15 watts for the Pass.  The Bryston hardly ever got really warm even when it was driven hard while the Pass does produce about the same amount of heat as four KT88 tubes I would say.  The heat from the Pass is not bad but just be prepared to use your air conditioning more.