Supe, welcome. It appears that you may be unnecessarily concerned over matters that have no factual basis, but instead are audio myths that you may have heard or read elsewhere. First, the power ratings of the Denons(and all other receivers sold in the U.S. subject to FTC regulation)are accurate; if they weren't they'd be in violation of the law. Lab tests consistently show that they meet and in fact exceed their ratings. My view is that the Denons should be back on your list.
Next, neither the Axioms nor the Yamahas(or any other competently designed receivers)are "bright". The Yamaha, incidentally, does have THX certification and should be well-suited powerwise for your needs.
Finding a receiver excellent for both music and HT should by no means be the "hard part". Sound is sound, regardless of whether it's Yo-Yo Ma on the cello or Schwartzennegger on the machinegun.
It's not surprising that your 55 is fine as to power, but that you'd like a unit with up-to-date features. If by digital SACD/DVD-A you mean a receiver that has i.Link or similar connection ability, consider the Pioneer 56TXi, available for right around $1,000. For well under $1,000, the Denon 2805, Yamaha 1500 or 2500 and the new HK 435 and 635(which might not be available for two more months, reportedly)are among the units which should meet your needs well. Of course, the appearance and feel of the controls are a matter of personal preference.
