cryod tube vs non-cryod tube

I just recently tried some el34 SED ( not Svetlana ) cryo quads and the difference is deffinetly there. At least for my system . If I was to put a percentage maybe 10% better. The difference I found was refinement all notes were crisper and had better definition ( not brighter ) in the highs, with the mids bieng a touch more organic ( a touch more meat on the bone ). And the lows didn't seem any difference whatsoever ( that I noticed ).
I will however by more of the same ,so its enough for me to re-buy and sheck out the extra cost.. This is only one situation and one tube type! I can't vouch for any others However, I just placed an order for 2 other pairs.1 Pair 12bh7a GE cryo'd and 1 pair of EI 12ax7 cryo tubes.I hope they work as well as the others...Not sure if that helps or not....

I guess from what i am seeing a lot is some sellars are cryo-ing " new production tubes" where there isn't that much risk ( as Albert mentioned ) to either party involved. For me buying a cryo quad of el34 SED at $150 -$175 a quad is better than 300-500 quad of nos el34 tubes. Being the Cryo quad to me is/was better it was worth the risk. I also think ( as mentioned ) not all tubes sound better cryo'd ,and thats why you see sellers carrying only certain brands and types to be cryo'd and logocilly ( i hope ) the ones being cryo'd should be the tubes that work well with the process...

Diamonddude18 : I can't say to be sure but my guess is these tubes would/should be checked for noise etc. after the cryo process,and do to the expense of the process I would assume ( again )theres probably a failure rate on some tubes that don't make it thru the process. A while back I had checked on the price ,if you were to send lets say a quad to have cryo'd.The cost was $10-$12 per tube.That may or may not be true now. My El34 SED can be purchased online for $75 ) aprox ) a quad. I paid $150 cryo'd ( price is with new tubes )...These are Pearl Cryo's.They were purchased at The tube depot..They have many other cryo'd tubes available. Nice people to deal with too.