Pass labs xa25 amp and BW 804 d3?

Awesome! Glad to hear you're pleased with it! Let than warm up before listening. Give it a good hour at least. I give my F5 2 hours but it clearly opens up around an hour depending on ambient temperature. That thing should idle as hot as a mug of coffee. 120°F or more. 

Although I suspect that you would have been very likely satisfied with the Parasound A21 amplifier I believe you selected the better sounding amplifier. I’m glad you weren’t swayed by those suggesting the Pass XA25 would be under powdered for your speakers. Congratulations and I’m happy for your very successful outcome. You describe the sound quality as "spectacular" that pretty much says it all. Just think about this, sound quality will improve as hours of use accumulate. 
Charles

Completed my demo of the xa-25 a week ago. It was a great amp. Smooth and warm (warmer than my Coincident Franks) and really nice bass performance. In the end I did decide to stick with the 300bs however. They were a bit more "real" and holographic. I think maybe a bit more accurate too as far as imaging goes. Close call though, the pass was really a great amp.

I had B&W Nautilus 804s for years, and have heard most of the B&W lineup over time. I can tell you, without reservation, that B&Ws are power hungry and, IMHO, need at least 150 wpc to even begin showing what they can do. Personally, I paired them with a 225 wpc power amp and they sounded good. 

I'd be wary of taking too much stock on the built in meters on amps. It seems to me that most are at best a rough guide and not to be confused with calibrated laboratory test equipment.