Switching to solid state amp?

I had a pair of QuickSilver M135 monoblock tube amps for 24 years.  No repairs other than 4 full sets of tubes (& a few fuses blown by over exuberance or an EL34 tube failure).  
I bought a pair of McIntosh MC501 monoblocks, and on the same speakers side by side it was VERY hard to tell the MC501's (SS) from the M135's (tube).  I really think its those crazy output transformers in the McIntosh.  Only other SS amps I've liked Bryston 28B monoblocks. (I've heard several other Bryston amps, but they sounded terrible!)
Now, the MC501's were bought used from a dealer who bought them back from his customer who bought them to replace his VTL tube mono's.  After 6 months he wanted his tubes back.

Ralph the amps are about 15 years old.  These are George Wright Sugnature amps.  Very nice when they work. QS 135 thanks for you info.  QS are quite nice.

I tried to switch back to SS amps for a while, didn't work.  I got tired to the heat and maintenance issues.  At the time, I was using VTL 300 Deluxe MB's. I tried 3 or 4 brands of amps  Bryston and Classe and a few others.  This search went on for a years.  In the end, I purchased another VTL but this one needs very little maintenance. It Fault Protection and Auto Biasing features but it still gets hot.  Then again before the I went with tube amps, I had Krell and they were just as hot.  Years ago there was a thread here titled "Cooking With Krell"  pretty funny posts,

I lived with Krell for years before switching to Classe Delta series amps. While Classe had the mid bass and high frequencies right, they lacked the low base punch of Krell’s. 

I then switched to Modwright KWA150SE for couple of years. To my ears, they had the best balance between SS and Tube amps. While attending RMAF couple of years ago, I heard one of the rooms with bi-amping setup of Tube and Class D amplification. I was literally blown away by the soundstage.  

Had to replicate that setup at home, right! So now I am running a ARC VT-80 with THOR mono’s powering up my 800D2’s. This is by far the best setup and sound I have had going back 15 plus years. 

Ralph the amps are about 15 years old. These are George Wright Sugnature amps. Very nice when they work.

George (may he rest in peace) was pretty competent and there should be no reason to think that the amps can't be refurbished properly. If you really want them to work right over time, I would consider having the filter capacitors in the power supplies replaced. While they are not really so old now to be a problem, in five years they will be.

If these amps have made it 15 years already they really should be able to do that again if properly maintained, which really should only be about the tubes once the power supplies are sorted.