My hope is to retire in ten years, and thus I've done yet more thinking.
My MCD301 has been out for repair (since Feb. 8!!!). The worst-case scenario, as I understand it, is that the drive needs replacing, which would cost over $800. After some thought, it might be a good idea to start saving money against the possibility of repair or replacement of other components, including speakers.
The Mirages had their 21st birthday recently; my turntable is approaching 22. While I'm thinking that if my turntable goes down in the next 5 years I'd replace it, after that I'm inclined to let it go and downsize. That would clear four shelves (current configuration), not to mention the space gained by getting rid of my LPs. But speakers would have to be replaced. There won't be a lot of money to work with regardless of what I can save (NY is expensive), but I'm hoping to have reasonable alternatives when the time comes. So in a way, I have decided to replace my M-3sis. Just not now.
The other factor is a probable need to relocate upon retiring, so spending a bunch of money on speakers would be unwise. At this point, I keep an eye on Def Tech, Mirage's OMD-28, Focus Signature SE, Bryston Model T, (I may have to think Middle T by the time I'd have to buy something, though), and the Axiom LFR1100. I'll surely want something with comparable specs to my M-3sis. My Mirages perform so well I can't imagine just dumping them, and listening to ELP's Tarkus last night, though with a substitute CD player, confirms that notion. However, I don't think I will try to fix them if they go down.
So, this is where I am.