Amp craftmanship/Quality

I'm not so concerned how a  amp/line stage pre amp sounds. 
No not really, MY main concern is how ~~reliable~~ it is.
To me, all tube amps sound pretty close the same.
The most single factor of importance is ~~The Reliablilty Factor~~.
Repairs as you know are expensive, not to forget the suffering involved. = Pure hell. 
I own a  Jadis Defy 7, no repairs running 7k+ hrs,(20+ yr old amp)
Knock on wood.

I had a  Cayin CD17 tube player, 8 yrs useage, no repairs,.
This is what I am talking about.
I want a  amp that will  perform day in, day out, month after month  year after year, decade after decade, with no repairs.
Quality of build is everything in a  amp, Far less imporatance how it sounds. 
How it sounds is not a relaiable factor, as each of us has a  different set of hearing. 
I think most topics here are concerned about sound, and less about The Reliability Factor.