I have compared both amps. If you are satisfied with the "house sound" of the Quicksilvers I would suggest staying with the Quickies. I say this as the Quickies I have heard sound similar in the mids and highs, and as you go up the line in power of the monos, the bass becomes better, with more control, better seperation, and greater finesse and ease of the musical presentation.
In general, in my experience, the Rogue M150's had a bit tighter and more controlled bass than the Quicksilver V4's. However, the Quicksilver V4's were more liquid and slightly warmer in the mids. The Rogue M150's just kept seeming a bit cool to my tastes. Almost so neutral it didn't have the flavor of tubes to it. To me if I wanted that sound, I would opt to go with a McCormack, Plinius, Ayre, etc. solid state that had the overall sonic landscape without the fuss of tubes. Again, to me, the Quickies did what I expected a good tube amp to give you... very neutral across the spectrum, however the strings, vocals, etc. had the liquidity and harmonics sometimes it only seems you can find in tubes. Don't get me wrong, the Rogue M150's were good and had that too, just to a much lesser extent. So much so, as I said it seemed more solid state to me.
Listening was on Meadowlark Blue Heron 2's, with the Rogue 99 Magnum preamp, Audience Au24 cabling and interconnects, don't recall which Musical Fidelity transport, but am quite sure it was the Musical Fidelity 21 DAC.
Everything is so system dependant, and both are good amps, it just comes down to personal preference and then fine tuning with synergistic cables and such. Good luck to you.
In general, in my experience, the Rogue M150's had a bit tighter and more controlled bass than the Quicksilver V4's. However, the Quicksilver V4's were more liquid and slightly warmer in the mids. The Rogue M150's just kept seeming a bit cool to my tastes. Almost so neutral it didn't have the flavor of tubes to it. To me if I wanted that sound, I would opt to go with a McCormack, Plinius, Ayre, etc. solid state that had the overall sonic landscape without the fuss of tubes. Again, to me, the Quickies did what I expected a good tube amp to give you... very neutral across the spectrum, however the strings, vocals, etc. had the liquidity and harmonics sometimes it only seems you can find in tubes. Don't get me wrong, the Rogue M150's were good and had that too, just to a much lesser extent. So much so, as I said it seemed more solid state to me.
Listening was on Meadowlark Blue Heron 2's, with the Rogue 99 Magnum preamp, Audience Au24 cabling and interconnects, don't recall which Musical Fidelity transport, but am quite sure it was the Musical Fidelity 21 DAC.
Everything is so system dependant, and both are good amps, it just comes down to personal preference and then fine tuning with synergistic cables and such. Good luck to you.