I may not be giving a fair comment because i have not heard all of these amplifiers. I was a Sumo Dealer way back and sold a good friend his Polaris. A year or so ago, he gave me that polaris. Being nearly 40 years old, i decided to recap it. I upped the supply caps with about 50% higher uf rating and bypassed each with 10uf mkp. I replaced the polycarb input cap with a polyprop film & silver foil and replaced all the chiclet mylars with film & foils. There were 4 small electrolytic on each board and I replaced 2 with Panasonic FM and the other 2 with Nichicon KZ, Lastly, there is a larger, if I recall correctly 16 or so uf electrolytic on the board. It is need anywhere from 4 mic to 20 mics there and I replaced it with a 10uf mylar. I have a pic or 2 if you are interested.. I have to say, this ended up being very noticeable improvements. Firmer bottom, very smooth midrange and a new refinement on top. I can’t comment on how they compare, but for about $100 in total parts, This has been a welcome improvement on an already decent amplifier