Hi Falconquest,
Let me offer you my take. I currently own a Burmester 956mk2. It is the best amp I have ever owned. It combines the best qualities of solid state and tubes. I have never owned the 2 Plinius amps you are considering but did own the Plinius 9200 integrated. I liked the Plinius a lot but the Burmester is in another league. On the other hand, it is not a fair comparison due to the tremendous price difference between the 2 products. I owned the Pass Labs XA100.5 monoblocks prior to buying the Burmester amp. I sold the Pass Labs amps as I found Burmester to embody the best attributes of Class A sound and yet have more dynamic slam compared to Pass. I am not sure if you can extrapolate my experience with the Pass Labs Class A monoblocks to the Plinius Class A amps you are considering. All I know is that buying the Burmester put an end to my amp search. I have owned it for almost 2 years now. I will say that if you go for Burmester, my suggestion would be to buy the cheaper 956 as it does not suffer in comparison to the 911 which is twice the price. Saving a few bucks never hurts!
I hope this helps.