Portal 2 "Potato Sack" ARG and first day downloadable content has caused some users to lash out at the game in Metacritic, which has caused the game's user score to drop as low as 5.1 - it's currently at 6.0.
The first day DLC includes the same sort of visual flair items that players have enjoyed in Team Fortress 2 for years, except instead of hats, the DLC includes items for P-Body and Atlas to wear, like a mustache, a one-lens pair of glasses, unique gestures, and various hats (including a selection of six items that can be brought over from TF2 if you own any of them in that game). Some of the more obtuse complaints is that when the game autosaves on PC, it tells the user not to "turn off their console".
Part of the issue seems to stem from the perception that Valve always gives away content; last year, they gave Portal away on Steam. But the main issue is that no one is forcing users to buy new content, nor purchase any of the "Potato Sack" games, just to get an earlier release.