I've always had tubular wheels, and have bought quite a lot of NOS tubs but have not used them all that much before. But I've decided to use them more now.
I've probably got enough so that I'll never have to buy anymore. Some of them are at least 15 to 20 years, and one pair must be more than 25. I think I'll first use the newer ones first, eg the Thailand made Vittorias. The big problem is how long will they stay in a good condition, there's no point of saving them if they just dry out and crumble to dust, which they will eventually.
Some of the stash:
I always try to repair a puncture, it's actually quite straight forward once you've found where the hole is. If the hole is tiny and it's a slow puncture, then it's a bit of pain trying to find it. Sealant might be OK for tubs like Tufo which are not repairable, but I'm certainly not going squirt some horrible gunge into my nice lightweight tubs.
We all know tubs are great but it's not just the tyres, I think it's also the rims; the classic shallow box section sprint rim is always going to be stronger or lighter than a HP/clincher rim, and I think more comfortable.
However there are some drawbacks:
Latex tubes; need to keep the bike off the ground if you're not pumping them up regularly. Training tubs don't have this problem though.
Not practical if riding for any length of time away from home, like touring. I suppose you could carry 2 or more spare tubs and do any repairs in the evening during the overnight stay but HPs/clinchers are more convenient in this case.