NOS Tubes--Are they worth it? or accurate?

After doing considerable investigation, I question whether it is worth it to undertake the quest of finding NOS tubes. Just looking at the volumes of discussion on audioasylum about Amperex 6922's and how many of them don't sound that good, the fakes out there, the difficulty in confirming how much use the tubes have seen. It just seems like way too much to deal with.

I know many will say, buy from the reputable tube dealers, but at what cost? Is their inflated pricing worth investing into something that has a limited life and can quite probably never be replaced? I think that looking into current production tubes that sound good would make a lot more sense.

The other issue is that many of the amps and preamps we are using them in are were not designed around the sound of these NOS tubes. If you substitute another tube, I think you are drastically altering the sound from the designer's attempt towards his version of reality and accuracy to something that is totally unrelated to this man's intentions and work.

It seems that we then end up with a mish-mash of sonics that are tailored to an individual's preference and may be far, far removed from any accuracy at all.