levinson differences

Do all the levinson amps (old and new) have sonic differences? What about vs ayre, krell, etc.
Are they neutral or warmer sounding in midrange and highs?
I bought a No. 23.5 and a No. 27 and I will never part with them. For the money the 23.5 is absolutely the best amp I have ever owned. I keep thinking about the Pass Labs X350.5 or X250.5 but the price is way out there. I'd think it better to put the money into new speakers. I have had the amps over three years and have replaced just about everything around them. They sparkle ... tons of power, delicate sound but more than capable of driving anything. I was running them in bi-amp mode for a while holy cow ...

I also run tube amps so there are aspects of the Levinson amps that can’t quite give me the joy of tubes BUT they just run. Both Levinson amps are very capable in terms of woofer control, when I switch back and forth between the ARC VT-100 and the No 23.5, the Levinson bass jumps out at me; especially as I start to turn it up. Very controlled, very tight – the tubes get a bit mushy.

I’m running Aerial 6 speakers and the imaging is fantastic, you can pick instruments out of a band. Guitar solo’s just don’t sound the same on anything else. Very non-fatiguing combination, I can listen for hours. If they start to go, I am considering a trip back to Harmon and pay the big bucks to get them restored. Hard to give up on a winner. I'm a tube lover but I'm keeping the 23.5.
I also like the series 20 (23, 27, ref 20) amps. I currently own 2 pairs of Ref 20.0 and prefer them to the more forward sound of the 20.5 and 20.6. I do not think these amps are that great in terms of low frequency control though. Krell is much better in this department (same approximate years of manufacturing). They have a higher damping factor and just do bass better.

The 300 series was good but a little more analytical. Still had the "dark" characteristic of Levinson, but not as dark as the 20 series. It has better bass control than the 20 series.

As to the 400 series I have no experience with those. I also have no experience with the very early Levinson products, such as the ML-2.
The 23 and 27 series are more laid back and softer sounding than the .5 series. The .5 series midrange was more prominent with better woofer control. The 300 series is more refined sounding and maybe a tad analytical or neutral IMO. I like them both. The 300 series are IMO the best looking amps ever made. Damn what a work of art.