I run a combo of NOS vintage tubes and new reissue tubes. It depends on where and how they are in the circuit. Personally, i think that in many cases, one gets possibly a more reliable tube with some of the reissues. Simply because the NOS tubes, like the 50's and 60's tele's etc are really unknown as to their usage. I can't say how many times i have bought NOS 'vintage' tubes only to look at the tube pins and to know that this tube is more than just used. Do NOS vintage tubes sound better than the current reissues? In most cases, i would say they do, but again, depending on where in the circuit.
Today, I also think that some of the new power tubes are superior to the power tubes of yesterday, certainly in SQ, maybe also in reliability. ( although that depends greatly from tube to tube).
Would I discount a good piece of tube gear if I could not use a 'vintage' tube in it...absolutely not.