Pass gear has a natural, warm and laid back sound. You can listen to your system for hours without any fatigue. Soundstage is big but accurate.
Nothing is without compromise and Pass is no exception. It’s not going to have the surgical precision, separation, bite and dynamics. It’s not analytical. It’s going to make even less than perfectly recorded music very palatable and enjoyable.
It’s been a while since I heard a Krell amp so I won’t even assume what that particular amp sounds like.
However, one amplifier you should add to your list is Coda No.8. It has the warmth of Class A but is a more articulate and accurate than Pass without being fatiguing. It will also cost less than the X250.8
You can’t go wrong with either Coda or Pass. And yes customer support is excellent with both (Krell is not in a steady state yet after the passing of the owner).
I would not consider McIntosh - just personal preference as to me both Pass and Coda sound superior.