i've got tung sol 6550 reissues but they are from 3 yrs ago. no problems with them, bought from TCTubes, sounds pretty nice might have a little less headroom than other tubes.
i've had the amp in a few times to reset bias and balance, one time it was sounding kinda weak because of the preamp tube in v1, swapped it out with something different and it made the amp sound stronger.
i play a passive pbass, and the amp likes a strong signal at the input.
fyi from what i've read, beans and toast has explained it many times, different batches of tubes will be different so while my tung sol's have been great they might not be as good now...or they might be better...
when i retube it i'm going to use the JJ Tesla 6550's i think.