Nice to see the Rogue Cronus Magnum II/III gettting some love here. I just purchased one after 2-3 years with SS (Belles Aria), and am loving tubes! May keep the Belles for the summer months as the tubes do throw a bit of heat into my 11'x13' room.
I find the Rogue CM III has better (incredible actually) soundstaging, detail, and low end vs. the Belles. The Belles can sound a tad on the bright side but "hits" harder. Put on Billie Jean by Michael Jackson and the bass drum will go through your chest.