I took delivery of my SA-BX500 via UPS tonight and, after letting it warm up some, replaced my SA-XR55 by connecting my other speakers & gear. Attached are:
- Wharfedale Pacific Evo 40 towers (bi-wired), an Evo center and two Evo surrounds - no sub;
- a 60GB PS3;
- a Comcast Scientific Atlanta DVR;
- a Panasonic DVD changer;
- an Apple iMac via a long in-wall RCA-stereo cable run, serving as an MP3 jukebox;
- and a Panasonic G-series 32" LCD TV.
First off, it's no
worse than my XR55. Courtesy of the skills I acquired futzing with the earlier model's interface, it didn't take long to hook up and configure. The TV runs to both the AVR and the PS3 via HDMI, while the DVD player goes directly to the TV's composite jacks. The Comcast box is connected only to the BX500 via HDMI (used to use digital optical); the PS3 is jacked in via digital optical and the DVD player is using digital coax. The iMac runs to the CD input.
Last, I turned Viera Link on, because my TV & AVR can use that - just for kicks.

The BX500 did think my center was a Large speaker after auto setup, but I changed it back to Small. Frankly, all I hope the auto-setup did was to set the speaker levels and distance properly. Anything else should be gravy.
The radio auto-tunes better and reception is fine, though there's an odd desynchronization (delay?) present that the XR55 lacked. I was able to play another radio in another room with the former model and have the sound seem uniform & simultaneous, but now there's obviously two radios playing.
I might say that it's slightly more transparent than my XR55 while playing MP3s or internet streaming audio from my iMac, but that's really an academic debate to me. It's plenty good enough, as was the previous model.
I haven't had the chance to watch television other than yes-I-hooked-it-up-correctly, and I will say that HDMI does simplify the connection business. I would say that using HDMI points out one of the BX500's flaws: you can only reassign/rename one of the three HDMI ports. I can't have HDMI #1 be CABLE and #2 be GAME? That's just stoopid - bad Panasonic, no biscuit!

I'll live, and I knew this was the case ahead of time, but it's just sad to see a good piece of tech hobbled for no reason but a company's internal marketing politics. ("Panasonic makes DVD recorders and BluRay/DVD players, so we must reserve those slots!") I'm only doing 5.0 anyway, so digital optical/coax is adequate for my needs. But if I desperately wanted to run full HDMI, I'm unable to accurately label my inputs, which gets a nerdy thumbs-down from me.
That said, it seems like good gear so far, and an adequate and more future-savvy model than the XR55 it's replacing. I'm pleased with the purchase, and I'll see if there are any hidden gotchas over the days to come.