New tubes in Rogue M-180 Monoblocks


I understand the M-180s now ship with the KT-120 power tubes, instead of the KT-80. You can also simply replace the KT-80 with the KT-120 if you already own these amps. I'm curious whether anyone has done it and what their impressions are as far as the difference in sound. Is the over $300 upgrade worth it?
actusreus
Since I don't know that much about tubes in general, I have to ask: what sonic benefits are to be gained from biasing tubes higher than the recommended setting?

Does someone try running KT-150 tube on Rogue M-180 amp ?

Rogue has said this is not recommended. I tried an octet of KT150 in my VAC 200iQ's and they were just awful. That amp was designed for KT88 too. I think KT150 is best suited to amps designed around it. 

Just last weekend I finally tried Gold Lion KT88 in my Rogue Apollo Dark. And surprisingly, it's way better than Tung-Sol KT120 (this was a fresh set too). It fixes the dry midrange without affecting dynamics. It's way, way more effective than triode mode if you find your Rogue amp sounding a bit too "solid state" for your tastes (especially in midrange). And the bass of the big Rogue amps is absolutely amazing - nothing else like it.

Sad times to discover this now, when the Gold Lions are hard to get :(

I wish Rogue had been shipping these with Gold Lions all along. The original design, when it was Zeus, was also designed around KT88. I recall Rogue went through some issues with the Electro Harmonix KT88 in the 2000s (some bad batches there) so they were all to happy to switch to the more reliable KT120 when it came out. But the KT88 issues seem to have resolved since then.