I saw a 5010 next to a 5080 yesterday at the local box store. I think the 5010 was just a bad sample:
It had 1080p and you could see some minor improvement close up in the details (feed as bad as it was though). But after I tweaked the settings on the two sets the 5010 black was a hair lighter than the 5080. The strangest thing was that the AR screen was ALOT less effective on the 5010 and there were alot more ambient light reflections (it looked like the sammy glass). You would think they would be the same. If all 5010s were like this then I would say the 5080 was the better set.
Like I said...probably a bad sample.