A big negative for the 3k ultra and the 8k ultra is the fact that the l1 and l2 roller inductors were made by Henry Radio. So if they end up having a serious failure then your in trouble. Unless you want to spend big bucks to have new ones custom made.
Its also a common for the roller wheel on the l2 to have problems.
Im getting a little off topic. This has been a great topic with a lot of very informative replys
The roller in my 3K Premier (vintage 1986, I had the first one ever made) was also fabricated by Henry. However, they had them in stock. They still might, I don't know. The amp shop is still there, even though they're not cranking out tube amps anymore: They do still service them.