Pass X-250.8, X-250.5 or XA-30.8...or?

Keith great choice. I have a feeling the YG, Pass pairing will be excellent. I talked to my local YG dealer about this, he runs BHK300s on his Sonja 1.3 (hes upgrading to 2.3 soon). I mentioned Pass and he seemed to think the BHKs would definitely be better but I think he underestimates Pass. They make fantastic amps. Please let us know how it works out.
Which Luxman did you have?

I've owned the BHKs as well (and tube rolled) - did not find them the right match. Luxman m900, Rowland 625s2. I've considered the Hegel as well but hear it's quite forward sounding which isn't my preference.

The pass monoblocks got better over time gradually because I made changes to room acoustics as well as cabling and vibration control devices.  This got me 80 percent to total happiness.  I then changed my turntable cartridge from lyra kleos to koetsu platinum signature which found used on audiogon and that was the final element needed to make everything sound glorious in the midrange and a tight bass.

The dartzeel is in a different room with different equipment including dartzeel preamp so hard to compare the amps in terms of how close pass gets but would say if had to buy new would be very content with the pass at half price.  However used they are roughly same price nowadays and would buy dartzeel first as it still more magical.  That said dart amp should be played with dart preamp as that is where magic occurs and pass better if driving less efficient speakers than 90db so really system dependent.

I have not heard newer lux and frankly if luxman monoblocks were not twice as much as pass 260.8 would have auditioned them.  I was offered great price but still over 50 percent more than pass monoblocks and so was non starter.   I dont think a stereo luxman would be enough power for harbeth 40.2 to fully make em sing.

I have heard chatter that luxman stereo has many qualities similar to dartzeel so must be impressive....