How far have ss amps really come in the last twenty years?


I have owned and enjoyed my Jeff Rowland model 8 ( recently modded and upgraded by Jeff to the last version) for many years. I recently had the opportunity of comparing it ( after mods) to a few of the current ss models from Gamut, D'Agostino, YBA, Parasound, Sim audio, CH precision, Constellation,PS audio,Pass Labs  and Musical Fidelity. The results were very interesting, because to my ears and in the systems that we did the comparison, the Rowland held its own against all but the most expensive D'Ag and CH amps. Even those were only very slightly outclassing the Rowland in the areas of top end resolution...and a tad in the bottom end resolution. Now the thing is that the last revision to the Rowland 8 was designed by Jeff over ten years ago! 
So, my question for those more technically inclined than myself is...how far has the design of ss amps come in the last ten...or even twenty years? 
128x128daveyf
Just to be clear...I am CERTAINLY NOT saying that there is no difference in SQ between ss amps. I have heard many ss amps that are strident and non-resolving, among many other issues that they have. OTOH, I am questioning whether there is that much difference between some of the top flite ss amps of today- and the top flite one's from as far back as twenty years ago.
I think that the improvements in SS amps exceeds those made with tube amps. Years ago there werent many SS designs that I could enjoy. Now there are many, mostly from Europe and very expensive. 
Hi Davey.... I've been searching for this noise for over a year.  It sounds like a resonance....so I banged on everything in the room - nothing loose/vibrating.  The sound is there on CD and Vinyl, so I thought it might be the speaker - Vandersteen 5A.  I reached out to Richard who suggested it sounds like the support cones are loose....checked - nope.  I removed the tweeter and sent it to Vandersteen.....fine.  When I got the driver back into the cabinet, I removed the midrange and sent it back to Vandersteen - fine.  I then removed the high pass filters from both speakers, the integral amps, and the crossovers thinking the factory would replace the batteries while checking for the noise (which they did)... but they also told me there was nothing wrong with the components I sent to them.  The noise is not coming from the preamp, because I have a dedicated amp for the earphones, and - no noise.  This is very interesting, and a real project.   I'm off to the audiologist for inspection....we'll see....(hear)
All I can say is; I once owned a fully refurbished, by Krell, KSA-250 amp and to my ears it sounded wonderful. Even my wife and children commented on the superior sound quality. Tight deep bass and superb transient response. It seemed to take a firm grip of my speakers (B&W N801 at the time) and made them do what it wanted to do. Seven years ago I sold the Krell and have regretted the decision ever since. So yes, if in top notch condition, some older SS amps can sound wonderful. The key words here are; CONDITION and SOME.

This is what Robert Harley said about the Krell KSA-250 27 years ago: https://www.stereophile.com/content/krell-ksa-250-power-amplifier-robert-harley . 
mgatt, you should have heard the Krell’s replacement ( whatever you purchased to replace it ), in your system before you sold it. Live an learn. Enjoy ! MrD.