I have compared sound, reliability, life from cryo and no cryo tubes.
From my testing over the years here is what i experienced:
1. Sound - definitely different , dont have golden ears so cant say which is better
2. relibility - cryo by far - tubes fail overtime not imediate nuclear explosion lol
3. tube life - really depended on unit used in sorry, appeared equal to me
These are just my observations of cryo parts since I started getting them done at my days at Varian in the nineties.
I also have had cables and complete units cryo before, sound on cables different use, whole units do not know but was free so tried it.