If you check with Chad Weaver, Brad Paisley's tech, you will learn that I have him on a schedule of changing output tubes in as little as 30 hours ... ten shows. We all see a difference.
On preamp tubes .... they can last for decades if NOS.
I personally do not like short plate tubes for phase inverter use as they compress too quickly but that is my personal preference. The Tung Sol Reissue is a short plate. I prefer the Sovtek 12AX7LPS for new tubes or some of the long plate NOS tubes Mike at KCA has onhand at www.kcanostubes.com
On the output tubes .... unless you can get those TADs in a middle rating which means they are tested as per book spec and put out 48mA at book spec you are tossing away your money as your amp was designed around a tube meeting spec and if they are too hot they amp will run hot, tube life will be short, and the amp will sound harsh. If they are too cold they will also not autobias as nicely either and the amp will not develop full power, it will sound grainy and there will be much more crossover notch distortion. Either stick with the EL84S in a 5-6 rating (or hit Mike at KCA or www.tubesandmore.com and ask for Steve Martin or one of the folks at CE distribution to help get you a JJ set in the proper range.
Listen to what happens after as little as 100 hours in the future.
By the way ... in cathode biased amps it does not matter how soft or loud you play when it comes to tube wear because as soon as the amp is running those tubes are running at 100% or more output wise no matter what your volume setting. This is not the case with grid biased amps as a side note.