Older PURE CLASS-A Amplifiers


I am looking at some older Pure Class A amps and am curious as to are they as good as some newer amps like the Pass X150, and which ones are recommended, and have they been compared to each other anywhere? Thanks much for the recommendations.

I am considering the following PURE CLASS A amps:
Threshold T-50
Monarchy Audio SM-100 Monos
Monarchy Audio SM-70
Forte Model 4
tpk123
Krell KSA-100MKII - one of the best balanced and mid ranged voiced amplifiers of all time. Caveat- You must send it in to be serviced every 15 or 20 years! Power supply caps need to be changed as they dry out - degrading sound & bass performance. Highly recommended - if you can find one.
Bedini 25/25. If you can find one, buy a lottery ticket the same day. The 25/25 continues to astonish me!
Luxman M-05. 105 watts per channel of the absolute most beautiful Class A power that can be found anywhere.
Anyone compare all these vintage amps to the PASS .5 and now .8 series.
Are the newest .8 pass amps truly in a whole different league than the older amps mentioned?