Just got my "VIP" 552 yesterday and thought I would share my experiences with you all as I enjoyed reading other peoples' comments while I was waiting for my delivery.
Likes:
-Ease of pairing external audio device control to vizio remote
-Complete Comcast/Motorola HD-DVR control with Vizio remote. I was able to use all of my guide and DVR functionality from just the Vizio remote.
-Simple yet elegant look and feel to TV. I thought speaker bar would be tacky, but it's not too bad
-Excellent picture quality, everyone that saw it was wowed. I tried HD netflix, 720p cable, and 1080p Blu-ray. Disclaimer: I was coming from a 5 yr old Samsung 720p DLP.
Dislikes:
-Glossy surface on Vizio remote is already covered in difficult to remove smudges and looks old and abused (in my defence, my hands were clean prior to using remote)
-The "enter" button on QWERTY keyboard is way too small. For a button that is always being pressed, its the same size as the smallest button (which is small). I ended up just using the enter button on the actual remote which is not really convenient
-Putting the option to turn off the tech lights (which I'm sure 100% of 552 owners will do) under the "help" menu was not intuitive at all
-There was no feedback to the quality of the netflix stream. My 360 does a quick check at start of movie and gives you a series of green bars based on the quality of connection, even going so far to call the 4 bar setting "HD." When I made my 1st attempt to watch a Netflix, it looked like absolute garbage. I cancelled it, signed out of Yahoo on the TV (not sure if that did anythign), and restarted it and the second attempt rivalled the HD cable box for PQ, perhaps even surpassed it. It would be nice if there was some sort of indicator to the quality of a stream. I use a wired connection to a high speed DSL so the connection quality is pretty consistent.
-It seems impossible to delete an input name once one has been entered. I tried everything (including reading the manual) and couldn't figure it out so I just renamed it "n/a" which will forever annoy my OCD self. The manual referred to selecting and clicking the done button after enterring new name, but my input rename UI does not have a done button like it did in the manuals UI graphic.
Lessons learned:
-Through the HDMI HD cable connection, I had a thin green column on right hand side of screen and a hard to describe thin column of "fuzziness" on the left side of screen. I was able to kill the green line on right side by changing cable box setting to RGB, but the other artifact persisted. After spending 2 hours chaning every setting, that artifact remained. I ultimately was able to adjust the horizontal position and size so that both artifacts were "off screen."
-Do not try and move this tv yourself

I tried and prb permanently hurt myself
Overall, extremely happy with the 552 and can't wait to watch some more blu-rays tonight.