Marantz from Accessories4Less: feedback from buyers?

Broadus

I was about to order a new Denon X1300 for $399 from Amazon or Crutchfield but have read some threads about the better quality of Marantz receivers with music. My usage would probably be 60/40 or 70/30 music to HT, so I'm intrigued about the difference between the sound of Marantz and Denon receivers.
As you know, Marantz is a good deal more expensive than Denon, and the closeout price of the Denon X1300 makes that difference even more significant. So that led me to look at refurbs on accessories4less. A refurbished Marantz SR5010 is $500, $180 more than a refurbished Denon X1300 and $100 over a new X1300.
So I'm grappling with four things:
(1) How much better would music sound through a Marantz 5010 than a Denon 1300? Significantly?
(2) Would you recommend buying a Marantz receiver from accessories4less?
(3) If you chose the Denon X1300, is it worth $80 buying refurbished from A4L, giving up a 3-year warranty for a 1-year warranty?
(4) Would you look to something else, another Denon, perhaps an X2300, or another brand, perhaps a Yamaha?
FWIW, I'm upgrading from a Pioneer VSX-516, so I guess any of the above should be a nice improvement. I've upgraded my speakers to a 3.1 system: a pair of Q Acoustics Concept 20's, a Q Acoustics Concept Center Channel speaker, and an SVS SB12 sub.
(If I lived close to a Fry's, I would probably buy a Denon X2300 for $398 and not look back.)
Thanks.