I just got this about 2 weeks ago and this is what I've noticed.
The picture quality is great on DVD, Blu Ray and DivX, that's all I've tried. The streaming from Vudu and Hulu are both is decent. The streaming picture quality is great, the reliability isn't as great. I get great speeds on Hulu from my laptop, but this will drop at times on this player. I've been tempted to use a wired cable to see if that makes a difference (If it does, I could just return it for the 5500).
I have my player fairly close to my router, no more than 5 feet away. It does play well enough, but there are problems. I've been able to watch a full movie on Vudu and several shows on Hulu without any problems, but when the drops do happen, it is quite a disappointment and makes me wonder, "Is this really better than standing in line at the movie store or waiting a day for my disk to arrive?"
I really wish there was a better way to input text for YouTube and entering passwords. However, since usually I only enter this once, it's not a big pain.
I was very impressed with the AllShare software, it works painlessly to view movies, pictures and listen to music from my laptop. I was surprised to find that WMV Lossless and AAC files were not supported.
One thing that is slightly frustrating is the speed of the interface, it seems slow as if there is a slight delay when I press a key.
An odd thing happened when I had my USB key attached to this, it dumped two core files (Is this thing running Linux?). I have since deleted them because they were around 250MB.
I am happy with my purchase, it is my first Blu Ray player, but a little let down with the streaming abilities of this player (May change after I try wired). But, it plays Blu Ray, DVD and DivX files with no problems that I've seen. I really hope many of the annoyances with this player can be worked out with a firmware update.