Krell Evo One vs Evo 600e/900e

I’m curious what are the differences especially in clearity, bass definition & depth, 3D and presence. Newer is better?

I haven’t found direct comparison between them. Any personal experience would be welcome.
No personal experience- sorry.  But FWIW, if PassLabs has an XA-200.8 amplifier that is STILL not the equal of the XS-150 (with "less power"),
one can only assume that the BIG difference between the two is the outboard power supply unit with the XS line.  So the Krell EVO-1 would theoretically have the same advantages- the better circuit design, and a further separation amongst noise-producing elements.  Still, you would probably need one heck of a pair of speakers as well as the other components to fully appreciate the difference.
    I once owned a Krell FPB-300 (stereo 300w/ch) which did not get the same accolades as the FPB-600 (twice the power but essentially the exact same amplifier) as to sound quality.  This however did not concern me in the least- the magazine review(er) was blowing hot air as far as i was concerned.  He couldn't explain this "difference" in any detail, and
anything more than 200W/CH is already overkill for all but the most inefficient speaker systems. 
Must have been the nutty writer Martin Coloms.
Have tried Evo 600 and 900 but now I am using Evo One with Evo Two for Wilson Alexia. Evo One is far better amp than Evo 600 or 900. Totally different. Impossible to compare.