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

Hi heat - low driver control - not as dynamic at lower volumes as others - transparent but there are more transparent - but so well rounded and as a whole they are great but I do wish they grabbed ahold of the drivers a little better but that’s part of the give and take with the lush sound so it is what it is but still would like better control. I’ve owned Aleph 3, 5, J, 30, F2, F2J, J2, 150.5, 350.5, 250.8, 160.8 and prob few others I forget. They were all great. Best sounding - no doubt there - the F2J is best sounding - you just need the correct speaker for it but it’s so pure and perfect. If he could ever get that sound into 100watts he could charge what he wanted for it. 

Hmm.. California style...I mean Pass amps.

Mitch2,
I recently owned the GamuT 250i mono’s. Got them from Kyomi Audio. Awesome guy. I ended up trading them to Scott Walker for my Speakers. Really nice amps. I owned the Clayton 30 and 100 before. I really liked the Clayton’s a lot at the time a few years back. 

The GamuT’s only use a pair of big old welder type of output devices per channel. Kind of a cool approach. I found the GamuT to be much better amps then the Clayton’s but they should be as they cost way more. The Clayton’s were slower, more plodding but still had decent PRAT and bit more set back and laid back, warmer with a bit thicker in comparison. Still they were very nice but the GamuT was a very different animal. GamuT has a more modern, transparent, more resolute approach. 

I actually prefer my currant Pass amps the 160.8 to the GamuT. Fuller, bigger, lusher, not as quick but I’m a sucker for the Pass Class A sound. Always have been so I’m sort of biased.