What are the weak points of Pass amps and pre-amps ?

Inna, currently I have pass int-250 (again). Before that I had many integrated including bryston, plinius hiato, gamut 150le, pass int-60, gryphon diablo 300, luxman 509x. I had to sell gryphon diablo for financial reasons. In my system with my speakers (Sonus Faber Amati tradition) gryphon and pass-int-250 were the best. Initially I though pass is lacking dynamics, until I found cables and power conditioner that made it sound more dynamic and more explosive. The top end also became great - again proper speaker cables needed to extract everything that pass can provide. Gryphon 300 was better with dynamic swings and articulation but not much. Pass has bigger 3d sounstage. Weekness - some air between players is not as good as dagostino and gryphon.  Read Audiodorm review on pass int-250 were they give 92 points to this integrated and prefer it over accuphase 650 and luxman 509x. There is another reason I decided to get pass again - service and US made product.

Denon1, I remember that you got Gryphon Diablo. Yes, I would not expect Pass to match Gryphon in dynamics, resolution and instrument separation. And of course at this level cables and power cords are even more important that at lower levels.
Big 3D soundstage is great, this is very important to me, especially with certain kinds of music.

I owned the Pass XA30.5 and it put out very little heat into the room going 24/7.

I now have a pair of XA60.5 going 24/7, and do not notice a rise in room temp. I have the amps on 2 Inch maple boards. Electric bill is up about $30 per mo. when on 24/7.

Pass Labs gives me SOTA sound quality! Could not ask for more.

I like a dead quiet room, so I shut off heat or A/C when listening.