I haven't had any problems. Still using original tubes. They are run very conservatively by design. I don't expect to change tubes before I die. So it's not an issue.
Tubes becoming hard to get?
An article in today’s WSJ talks about tubes for both guitar amps and stereo gear becoming scarce due to Far East and Ukraine/Russian tensions saying most tubes originate from China, Slovakia, & Russia. As such, people are beginning to Hoard and retailers are beginning to limit purchases.