Highest BUILD quality tube amps?


Not so much with sound...lots of ways to fine tune thru tube rolling, etc. I'm just curious which tube amps are built to last for many years with the least amount of repairs. I know Mcintosh comes to mind for longevity. I was snooping around on the web and Air Tight seems to be built like a tank and I've never read any poor repair histories. Luxman same thing. Any others come to mind?
aberyclark
Check out Raven Amplifiers built in Texas.  They are works of art and the music is awesome.  I have the Raven Integrated Reflection MK2 tube amp.  With my tube rolling I am getting close to 70 wpc.  When people come to my house the first thing they notice is the amp.  The second thing they notice is the quality of the sound.  Dave Thomson has some of the finest historic tubes that he has collected over the years.  Check out their website - Raven Audio
I have had 3 Prima Luna integrated since 2013, upgrading each time. Currently enjoying the HP (8 KT150 tubes) and excellent headphone amp. Never had any problem, despite the heavy use. 
Do they have to be good sounding amplifiers or just well built? Should they be really heavy?