even better than the HTs are the copper foils and paper from Jupiter. Have used both, as well as the Duelands, and Jensen copper foils (Jensens are no longer available). The Jupiter copper foils are more organic sounding. Original poster did not mention what amp they were putting these caps in. On some older gear with high GNFB, you may not hear as much of an improvement as you would on amps with lower feedback.
Choice of capacitor
If you have to choose caps for your tube amp which one would you prefare
JUPITER COPPER FOIL WAXAUDYN TRUE COPPERJUPITER HT PAPER BEEWAXThe value being 0.33uf 600vdc
JUPITER COPPER FOIL WAXAUDYN TRUE COPPERJUPITER HT PAPER BEEWAXThe value being 0.33uf 600vdc