Well, I'm glad to see that Mike didn't keep this thread closed, if it was.
I just finished reading the thread. Interesting read and I'm glad it is still around.
First, about restoration. I've had a fair amount of gear optimized and restored completely. If it doesn't sound better after being restored, then something was done incorrectly in the restoration. Go back to your tech, or else revisit your work. After restoration, I have had two different results. In one case, I had a Pioneer SA-9500 completely restored and it didn't sound any better after than before. What that means to me is that the components inside the unit were still operating within spec. I didn't keep it because I was hoping to hear an improvement. In most other situations, the unit sounded anywhere from better to outstanding.
About McIntosh gear, I don't think I need to describe the sound to the members of the Mc Forum, but I'll summarize. I have actually heard speakers that didn't sound as good on my McIntosh gear. But it is also a subjective opinion because I have heard those speakers sounding better. My example would be Kef 105s on an MC-2205. They sounded good, but not great. And you will love this. I also have a fully restored Bose 1801 amp, and it plays with Kef better. Shortly, I will be doing an AB comparison of my Klipsch Cornwalls with the MC2205 and my Kef 107s with my Bose 1801. I'm very curious about the results.
I won't restore gear just because it is old though. That can get expensive. So I use it for a while, and I like what I feel and hear, I will restore it. To me, it is a keeper at that point. I would have done that with the SA-9500, but I assumed it would improve. It didn't. I won't always make the right choice, but I'm fine with that. I do know I want my keeper gear fully restored and if possible, optimized. What I mean by optimized is that when the gear was designed, the engineers had to design within certain restraints. Some components are now much better than then. Op-amps have really improved since.
I had my C26 and my 4401 preamps fully restored and optimized, and I heard some major improvements. After LeeStereo had optimized my C26, I did a side by side with a Dolan PM1 preamplifier after the designer had optimized it. I couldn't hear any major difference between the two, and following that, the designer came over and we ABed them again together. We came to the same conclusion. All subjective, of course! I did like my optimized C26 more than the Dolan PM1, but again that is subjective.
I love my Bose gear (1801/4401) and I love my McIntosh gear (MC2205, C26, MR74, and MA-6200) They serve different purposes in my house.