6H30p-DR vs 6H30p Tubes

Folks,

I have been listening to Sovtek 6H30p’s tubes for almost a year now on my ARC Foundation Series components. Since acquiring ARC, I have been wondering about the uber expensive NOS Russian Reflector 6H30P-DR tubes. 

Has anyone tried these tubes in their ARC gear? What I do not know is the sonic differences between the standard Sovtek 6H30p's and the more expensive variants, including the 6H30P-DR?

If I do decided to go for them, where do you think I should start off? I am looking at 8 tubes in total, 

ARC LS28 - Pre, four 6H30’s
ARC DAC9, two 6H30’s
ARC VT-80 - Amp, two 6H30’s

I would love to hear any feedback and the equipment they were evaluated in, if different than ARC. 

Thank you!