Just got it yesterday - here are my thoughts so far.
The packaging of everything was really good. A lot of gloss finish on everything protected by that plastic wrap. It was pretty straight forward to assemble and looked really nice. The setup was in my living room (about 12x16) with one side open to a dining room and then kitchen - all 8' ceilings. I first set things up so that I could compare my TV speakers only (TH-50PZ80), the SC-HTB550, and my 5.1 setup (Onkyo with Paradigm's). Obviously the sound quality of the sound bar fell in-between the TV speakers and my 5.1 setup, but it was definitely a noticeable setup up in sound quality from the TV speakers. The lack of bass from the speaker bar alone is definitely noticeable when compared to my L/C/R speakers with bigger woofers, but the wireless sub does a really nice job of replacing the missing bass. I'm guessing that a little playing with the placement of the sub will help it mesh together even better. I preferred the sound of setting the speakers up individually on the stands as it gave me a little wider of a sound field. They do attract fingerprints though - I already need to wipe them down after playing with the setup. Stringing the speaker wire through the stands was also a little tricky - I had to bore out the hole slightly in the stand to allow the wire to fit through. Not a big deal though.
I then removed my 5.1 setup so that I could hook everything up to the HTB550. I connected more devices to it now than I plan on having because the basement isn't quite ready to setup my 7.1 system. I connected a Panasonic BDP-35 Blu-Ray and a Roku XS box to the sound bar box via HDMI and then I connected a TiVo HD (HDMI) and a Wii (compoent) to my TV. My TV doesn't have ARC so I ran an optical cable back from my TV to the sound bar box as well. There's also an HDMI cable from the sound bar box out into the TV.
The Viera link seems to work just as I'd expect it to work. The only downside is that there is no numerical volume value or even a gauge that shows up when you change the volume. This may just be a personal preference, but I will miss having that visual cue (my Onkyo showed the volume on the LCD and an OSD). Can't just tell my son to turn it down to 10 when he's watching TV on Saturday morning...
There is a small oddity with the input selections on the sound bar box that I haven't quite figured out. I'm currently getting only video from my Roku on one of the inputs, but both picture and sound from the Roku on another input. I tried swapping devices and it seems to be related to that specific HDMI port on the sound bar box. I need to do a little more investigation about what's going on here. I'm wondering if this is because my TV doesn't have the ARC and the box is just showing a passthrough of the video of the last input?? The manual isn't overly extensive so I may need to call Panasonic if I can't figure this one out. I can still use the box fine, but I really wanted this to be a simple setup and don't want to have something like this in there to confuse the wife.
The Bluetooth functionality was really nice. I had no problem pairing it up to my phone. So much more convenient than hooking a cable up to my phone like I used to. I was able to get around 30 feet away with my phone in my pocket before I noticed that the connection started to have trouble. I did not try pairing multiple devices to it yet.
You can adjust the level of the dialog with the included remote, but I found that it really reduced the overall sound quality if I turned it up too high. It seems that you're sacrificing sound quality for the clarity. Still a nice feature to have though for those times when the dialog level is just too low.
Overall I'm pretty happy with the HTB550. The biggest unknown for me was the sound quality and I think it sounds great for watching TV, a casual movie, and also for streaming music from a phone. It doesn't replicate the surround sound of a 5.1 system, but that wasn't what I was looking for. I just wanted something that could give clear dialog with decent sound. Just a quirk to figure out with the one HDMI input, but otherwise I'm very happy with how things went.