Rogue 66 vs. 99, the magnum versions

I've listed this query before but am hoping for some fresh opinions. I've tempted to go for the 66 magnum. It will mate with a Parasound Halo 21 for MTM's and a Sonance 2120, 160W @4ohms, each channel for a sub in a push-pull single box sub. Surprisingly, the Sonance has a nice powersupply and seems stable for moderate sub bass duties once actively crossed @ 80hz. Would taking the 99 mag make so much of a difference SQ wise. The MTM's are efficient and use Scanspeak revelator 5 inch drivers with Aurum Cantus G3 ribbon handling frequncies above 2.6k or so.
I try to avoid hype. I'm looking for an accurate tube pre with the that 3-D, holographic imaging.

Thanks for any opinions offered,

Steven Hebert