Pass Labs upgrade?


Hi,
i am looking to hear from anyone that has/had the Pass Labs XA-60.8 amplifiers and upgraded to the Xa-100.8 amps. What was your experience like ? Was it worth the leap?
my speakers are pretty efficient @ 91 db but I am interested in the next model of Pass Labs for potential increase in overall dynamics.
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I'M quite happy with what i already have- ML-53 Mono's. You get a lot of power and very pure sound, and they get warm but not too hot.  Plus they weigh a "manageable" 135 lbs. OTOH, the Pass XA-0.8
series would have easily been my second choice; i believe they are as good as
anything out there including mega-expensive gear from Europe (with all due respect of course).  But... they get VERY HOT.  The cosmetics have
improved a great deal, but i still see no need at all for a bias meter.
Plus the XS- series is even better, and of course are big enough to be used as end-tables.  
     I will say it once again although "i know" that they are not nearly as good as the newer stuff, but the ALEPH line, especially the 1.2's, were/are superb amps- I know because I heard them and immediately wanted a pair for
myself.  And guess what- no one (seems to be) putting them up for sale.
Perhaps someday they will come up with a design that makes power efficiently and also sounds organic, that would be a major step forward.


We know that Pass Labs is the best SS currently. Any of you guys using these power amps on Thiel speakers?
Agree with reaching out to people including Nelson at Pass Labs. i was looking at the First Watt line but after several emails with Nelson, stepped into a xa30.8 with the xp10 preamp. He was very patient with my questions and helped me make an informed decision. 
any word on replacements for the XP-10 and XP-20, as they've been around 7-8 years now?