What are you talking about? 18th in what? 05 and 06 seasons with Oakland are irrelevant.
2007: 98 receptions 1493 yards 23 freaking touchdowns. EPIC SEASON
2008: 69 receptions 1008 yards 11 touchdowns - without Tom Brady for the first quarter of the season.
2009: 83 receptions 1264 yards 13 touchdowns.
The guys numbers are consistent, and hes right where he should be. He is definitely going to be better than average for the Vikings, if Favre can get him the ball.
My apologies, I should have stated what I was citing. I'm talking about Defense-adjusted Yards Above Replacement (DYAR). He was 5th last year, and he was 18th the year before. Just casually looking at his historical DYAR, his value seems to be proportional to the DYAR of his QB, which for a receiver, is not a good sign.
Those statistics you've mentioned are pretty much irrelevant, as they fail to address the quality of his QB, the situations he's been in, as well as the efficiency of the offense as a whole.
He's looking like he'll be roughly league average this season, which isn't to say he's not valuable, as especially the past 3 years, league average production from the WR position has been extremely valuable.