Ok, I have played around with the 550 for a couple of hours.
I like it the experience overall.
I need one more day to do some test of the files before I'll write more about playback.
There are some bugs with bd-iso/m2ts not displaying the whole picture. You can see only 1/10 of it and subtitles. I think this is a overlay issue because I have been able to get the whole picture back one time when switching in and out of the menues.
I tried 200 mkvsamples so far and most of them seem to work. Had black level problems with some so i need to check these on my computers aswell.
Menus
Cant use the remote A-Z with drop down boxes, eg selecting Sweden in Country (need to scroll instead or use +pg-).
Can't use 24h... only AM/PM
Weather report seems to be acurate.
Internet Apps
Youtube Video
* Very fast loading and image quality is ok (can see alot of DNR and banding/grading sometimes)
* Time scrolling is easy and works!
* Alot of alternatives eg categories/search/most viewed. (Cheerleading channel

)
* Adding a video to your playlist works, but it took me a couple of minutes to figure out how to go directly to the next stream in the playlist. (popup menu-> press down->press right)
* If you want to change to another stream while still watching something, you first need to stop the current one or use the solution above. (this is really stupid and must be changed. The user should get an option if he wants to add it to the playlist or go directly to the new stream instead imo)
* Avatar 1080p flash trailer (1920x1080 14.1Mbps, AAC 44.1Khz 2.0) worked without problem!
* Playlist automatically clears itself when everthing has been seen.
RadioTime
*The player hanges when selecting local radio channel (Bandit Rock 106.3). Needed to pull the plug.
Could repeat the crash by trying to select a couple of random stations again.
(player wanted me to send a crash report to Netgear)
RadioIO/Shoutcast
* Really good and fast. Didn't notice the same bug as above with this function.
Flickr
* Can't find myself on flickr, but found a friend. This must be some kind of settings with flickr preventing it from finding mine I guess
* Can't find my taged pics. But i found someone else who had tagged my pic somewhere
*Seems like you cant open a pic in someones stream and press next to see the next pic.
*Quality isn't very good
*Overall flickr-function needs alot of improvment!
News channels
Seems to work like it should. I can watch most if it... but not ABC News (maybe GeoIP)
Other stuff
*I had to restart the player a couple of times by pulling the plug. Usually when I change videos while already playing something or when watching something and suddenly the video stops. It doesnt help to soft reboot.
I can replicate this bug with one MKV with DTS-HD track!
* Back of the remote looks like bad suede after a while. The surface likes fingerprints.
*If you press back in a movie/youtube or whatever you will be taken to the menu and the video is still playing in the corner. The logical thing would be to press back to go back again, but instead they have choosen the menu button as the return button for this. The back button always goes back until you get to main menu.
*Sometimes when you use the search function in eg Flickr, CAPS is always activated. Guys coding these things apperently thinks every one always has the first letter with capital letters but forgot to make it auto off after pressing the first key.
*The stupid popup menu sometimes gets in the way making it impossible to click ok when browsing menus.
Eg if you are playing radio in the background and have the popup menu on. You have to manually deactivate it by pressing "Popup menu", but the back button is always working. This should/could be solved by an option to make the popup menu disapear after eg 10 sec.
*I miss a delete key on the remote when typing letters. Oh wait its the back button 5 cm away from the rest of the letters! <- Stupid!
* Miss that I cant put the cursor where I want when typing. I need to clear everything and write it again if i make a misstake