+1 here for the KT120's excellent reliability. I run these in my Quicksilver Mono 120s (2 pair in two systems), which all have well over 2,000 hours of use, and I've had zero issues...super reliable. I also love Shuggy KT-88's, which sound wonderful in my third pair of Quicksilvers (KT Monos). Again, fantastic, balanced, and dynamic across the board with no issues whatsoever.
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?