Interesting...
I would have to agree that, in terms of pure longevity, the award should almost certainly still go to McIntosh.
They've always been built like tanks... and tend to last forever.
And they have awesome resale value (at least most models - with a few exceptions).
I also has a McIntosh tuner some time ago that was probably the best-sounding FM tuner I've ever owned.
It was also far and away the most expensive - even though I purchased it used.
I sold it when it became apparent that there was nothing I wanted to listen to on FM.... and got back about what I paid for it.
However, to be quite honest, I have never been especially impressed with how McIntosh amplifiers sounded.
I'm not saying that they sound in any way... bad.
I've just always found them to sound somewhat short of neutral - usually tending toward the warm or soft side of the spectrum.
And, if you don't know me, you can tell from the way I phrased that... I think an ideal amp should sound perfectly neutral.
I've only ever owned one Bryston amp.. and I've never owned a McIntosh amp... although I've heard plenty of both.
I've thought that the Bryston amps I've heard generally sounded cleaner and more neutral than the McIntosh amps.
(And I think our XPA amps... all the way back to Gen1... also sounded a bit cleaner and more neutral as well.)
In my opinion there are far more important things in audio than longevity, but to each his own. If my choices were Bryston or McIntosh there is no question I'd buy McIntosh.