Weren't you using the 120's in your own amp recently for a while? I think that the longevity factor alone makes them at least a viable purchase at such a reasonable price and they would be impervious to any voltage wear and other wear factors the ST-120 would throw at them.
You said they sounded more or less like the KT-88's. At that price you would be buying a set of heavy duty tubes that are similar in sound and price as the Gold Lions.
I ordered a pair to see what's is up with them and will report my findings in due time.
I am using Gold Lions in my ST-120 right now so I will have an opportunity to make a good A-B comparison.
I don't need to squeak the last watt out of them. My ST-120 will blow up any one of my speakers as it is. I am currently using a set of Decware NFX's that I can only turn up to about 4-5 on my 'Bottlehead Foreplay III Extended". This amp already has big balls.
But as an audiophile I like to play at my hobby and that's why we are all here on the forum exploring new ideas and gear. I think we all have a little mad scientist in us.
I am also going to put one of those attenuator kits in my amp as soon as I have some more $$ and recover from the KT-120's purchase.
What else should we audiophiles spend our mad money on booze?
Me, I like tunes and stereo gear.Not to mention writing to fellow audiophiles on this forum.