Hence my focus on the power. :-) They're all going to sound a lot different in my room than they do in the store, and of course none of the stores have Axioms so you could basically write off the whole in-store sound quality comparison but for any blatant problems like audible noise, pop when the power is turned on, etc. None of these receivers should have those kinds of problems. I asked my original questions in hopes of not finding myself making three round-trips to the stores (bringing a different receiver home each time). I'm pretty sure the Denon will do the job admirably power-wise, but I'm not sure about the Yamaha. I question the Sunfire mostly because of the unconventional power supply (and no specs on output impedance or damping factor makes me question whether or not it's going to yield a sloppy bottom on the M80ti's). Bass drum thwap is important to me, I'd likely be really disappointed if I found the amp spilling its guts at high listening levels and exhibiting not-so-good slew rate and damping factor. One side of me is probably fishing for an excuse for more power :-), but I'd love to save $900 or more if I could (and just get the Yamaha). If money was out of the equation, I'd probably just buy the Sunfire (if money was no object, I could just buy the Denon too if the Sunfire didn't make me squeal with glee :-)).
In a nutshell, I guess the questions come down to "Is the Yamaha a waste of my time due to power requirements?" or conversely "Are the Denon and Sunfire serious overkill on power?"
I'm going to wait until after I've had the new speakers for a while on my current amp before deciding. If I conclude that my current receiver can handle it, it'll be a no-brainer (since it's weaker than all 3 of the new prospects). But I really doubt that's going to happen, since I'm not happy with the power from my current receiver and the Polk RT2000i's are similar in efficiency to the M80ti's (by specs, which could be misleading). It was more than sufficient for the room for which I originally bought it (our previous home's family room was smaller and had 8' ceilings), but it (and the RT2000p amps) fall short in our current family room.
The Sunfire True Signature seems to be perfect in our family room power-wise, maybe even a tad over the top. If it weren't for the deep near-room-length skylight wells and other openings, I think it'd be overkill for the room. But it's a different part of the story since I plan to only use it for movies, it's self-powered, and it's almost out of the equation for my desire for tight bass. Right now, the room seems capable of supporting tight bass, it's quite good up until the RT2000p's start fluttering and the Yamaha amp starts running out of gas (ruining the whole listening experience even if the bass is still tight :-)). An advantage of having the high arched ceiling and lots of openings, I guess (make speaker placement a lot harder though; the QS-8's are going to be an interesting problem :-)). Little did my wife know that part of my choice our skylight well design was acoustic. :-) Unfortunately I don't know if this helps anyone get an idea of where I am in terms of pwoer needs. The room is drywall all around but for the brick fireplace dead center on the left (brick is exposed all the way to the ceiling), the 2 sets of french doors on the left wall on each side of the fireplace (mostly glass) and the windows behind the TV (not much of a factor due to its position; the TV covers the whole thing). There's a window-like opening into the kitchen on the right wall that's near the front and about 4 feet off the floor (the family room is about 12" lower than the kitchen), and an 8'x8' opening to the kitchen on the right wall in the rear (making for lots of fun positioning the right surround). There's a short (maybe 10 feet) hallway in the center of the rear wall that leads straight back (making for lots of fun positioning a rear speaker for 6.1 sources :-)). The floor is an engineered ash (Kahr's Ash London), but it's almost all covered by a thick wool oriental rug (but for the area behind the listening position, which is not covered; the rear tends toward 'live'). There are 2 full-size leather sofas in the room, a big dog bed, a large travertine coffee table (300 lbs, practically dead center of the room), a smaller slate tile coffee table, a couple of barstools and a bistro table on the back wall, a pair of hardwood audio cabinets in the rear right corner, and half a dozen large plants. There's a good amount of room effect for mids and highs behind the listener, but in the front things are pretty straight, probably due to the rug and pad underneath it and the fact that the ceiling climbs away from the mains (it's practically impossible to get a loud first reflection from above from the mains to the listening position). Real problem areas would include lack of room to bring the mains more than a few feet from the front wall, so much stuff on the front wall that there are only a few left-to-right positions (two Bell'O ATC-2052MC and the Grand WEGA on an AVSC-2051MC consume much of the front wall), the aforementioned surround positioning issues (largely irrelevant to the receiver selection), and a tendency toward less room effect at lower frequencies than is typical of other rooms I've used for listening.
I'll post again after I've run the Epic 80 system on my current receiver. I can't wait for it to arrive!
