Monarchy SE-100 MK2 vs used Plinius SA 100 MKiii

I can't speak for the Monarchy, but the Plinius is an excellent amp, provided you can tolerate the heat it puts off when run in Class A, and provided that the amp remains properly biased. If you have a decent tech near you who could check bias, then you're okay as long as the heat is not an issue.

I use a pair of the se 100 deluxe one before the mk 2.GREAT AMPS.THEY DO RUN COOL FOR PURE CLASS A AMPS.EXCELENT VALUE FOR THE BUCK.YOU CAN NOT GO WRONG.

Can't speak for the Mk2 but I had original SE-100's and currently Plinius SA-100 mkIII. The Monarchy had nowhere near the bass and power with some speaker combinations but, apparently, that's been improved for the Mk2. Still, you're comparing 52lbs versus 75. The Monarchy also had a slight upper-mid/lower treble peak that I felt accentuated the soundstaging to the point of being a bit artificial. It can be a sweet amp with the right speakers. The Plinius, on the other hand, is laid back and understated, more than some prefer. It's not trying to impress despite it's capability.

Comparing new to used isn't fair. A new SA-103 is several times the price as the Monarchy's.

I want to move from Monarchy Mk2 to Plinius SA-100 mkIII.
Is it worth it? Will I get dramatical sound improvement?