I personally much prefer the 5751 tube group than any of the ATX tubes. There is a variety of them available at reasonable cost. One negative, they have a lower output than the ATX tubes by some 25%. Teles will last longer than any. On most speakers, ATX tubes sound OK. If you have ultra transparent speakers like an electrostat, you will hear the differences.
What telescopes do you trade in?
What telescopes do you trade in?