KT-120 Tubes


I have recently purchased an Audio Research VT-80.  As wonderful the amp sounds out of the box with stock Tung-Sol's KT-120,  I am curious to hear from anyone trying a quad of the Shuguang KT120's. I don't want to make the decision of trying them out based on Stereotimes review of Shuguang tubes, so any feedback on their sound would be appreciated. 

Any alternate suggestions on Sovtek 6H30's tubes is also welcomed.  

PS: The VT-80 is being used for mid's and high's in an bi-amping setup with McIntosh MC601's. 

The bigger question is if the KT120s can be replaced by KT150s. Many others (especially AR amp owners have reported significant improvements. 
With 6H30s, Gold Lions aren't bad, but somebody told me that are made in same factory but with better QA(i.e. bad tubes pulled out before sale). Corrections on this point appreciated. Cheers,
Spencer,  fortunately my AR can also accept KT150's. In fact, VT-80 can accept, 6550, KT88, KT90, KT120 or KT150.  

I will check out Gold Lions 6H30's.