NOS tubes are as varied as anything. There's not ONE sound. If you read audiopiles forums it seems some sound like shit and others take you to heaven...

As a practical/general guide, the best tubes are 60s European made (Telefunken, Mullard).

but in guitar amps, preamps, compressors, etc. especially guitar and bass amps, you think you can hear the difference between a regular tube and new old stock (particulary the ones you specified, telefunken and mullard)??

The answer is YES if you happen to get the "Take You to Heaven" picks compared to new tubes like Sovtek although I've heard some great new tubes by mistake.
LH