Clayton or Pass Class A, which one do you prefer and why ?

Did you ever consider full immersion cooling?

If your really interested and not just pi***ng in the wind.

https://www.stereo.net.au/forums/topic/33191-living-with-pure-class-a-in-australia/?page=4&tab=c...

I'd go with the Pass.

If you know anything about heat dissipation on heat sinks, the top mounted ones on some Clayton models are a not efficient at all for removing heat for Class-A heat dissipation.
You need vertical side mounted, and as many fins as possible. (thickness of fins are not important) surface area is.

I’ve made many very large pure Class-A amps >100w that heatsinks were not an option to use, as they would be as big as a coffee table.
I used a water cooled heat sink which was far better and cycled warmed coolant, through a slow fan cooled small radiator very effective but a very complex amp.

Cheers George