Summary: Just a quick review here, I have set up many Blu-ray players for friends, and these are my favorites. They work great, are full featured and have excellent remotes. Firmware updates are also very easy to apply. Unless you really want the backlit remote (not important if you use Harmony remotes like I do) or need the analog outputs you might as well save a bit and buy the BDP-S350. It's also smaller and a bit more sleek looking.
Summary: I have had this player for several months now. It has worked with every Blu-Ray disc that I have played in it. It does everything that a person could need. It decodes DTS-HD and Dolby TrueHD in the player and will output it to a receiver over HDMI or 7.1 analog outputs. It will also bitstream the DTS-HD and TrueHD via HDMI if your receiver will decode them. If your receiver is older, it can output Dolby Digital over the optical/coaxial outputs.
Summary: Bought this Sony BDP-S550 Blu-ray player about 6 weeks ago. My first Blu-ray player and so far no problems at all. Video and audio quality appears as good as all the positive reviews here state. Slightly slow on the load and unload of a DVD, but this is common to all blu-ray players. Plays standard DVD's just fine, but of course blu-ray quality excellent. Went for this model so that it doesn't become old technology too soon.
Summary: Comments about Sony BDP-S550: I use it to watch movies at home. I'm completely satified with its user-friendly settings and of course, the high quality pictures and additional features. The only inconvenient part is that it doesn't come with a HDMI cable. But do get a good HDMI cable in a store, it helps improve the quality quite a bit.
Pros: Backwards Compatible, DVD Upconversion, Easy Set-Up, Excellent Image Quality, Good Connections, Good Soundtrack Support, Upgradeable