Good bass, controlled bass. Micro and macro dynamics. The talk of highten bass towards mid and highs. Nah, forget that. That is simply a user, using speakers that are not suited for the room. The Krell amps drive the bassdrivers in a manner most would only dream of. There are many amp-makers that talk of the evolution of their brand. I have used Krell and many more, back in the days and heard Pass Labs. I would go for Krell. There are many krell-dislikers. Don't care about them. Of all the amps i've heard, older Krell amps simply rules in some specific key areas. The later amps are statement amps. The EVO amps are superb. I would not trade them if i had them.
Just listening to a good, or bad recording will reveal absolute inner detail in the bass area (hear they are true ref amps) . Most other amps will not do that. Also, the Krell amps are completely silent, no hum or background noise at all (no bass bloom either). Pass Labs, with all respect, i would listen myself. If i could not do that, i would go Krell because you will not go wrong with those amps you talk of. What is a thing to learn about the Krell is that they will not make bloom as with Pass. It is simply a manner of how you would like it. If you use speakers that has a tendency to sound cold or harsch you might like bloomy sound. But the later Krells are not cold or harsch at all. The c series and older could be hard in tone, but not from cx and forward. I firmy believe, if you have not used a Krell amp of that magnitude, you are in for a serious experience that is only possitive.
I seriously hope you see to it that you demop a EVO amp, you will be hooked directly.