It's possible I have the story wrong.
I know early in his career he was dubbed "Error-hoff" in honour of his brutal work in the defensive zone.
Being in San Jose, a defensively responsible system, proved stressful. Even as he approached veteran status, he still did tours of duty in the stands. The points per game looked good. The opportunity looked good, but SJ coaches would tire and sit him in the stands when they were stressed too much. He had 42 points in his final SJ season and a respectable TOI of 21:15 with 3:01 on the PP.
So, off to Vancouver he went. Maybe UFA or for very little. He found a coach that obviously was pleased with him. His TOI was 22:46 the first year and 24:00 the second, and he averaged 3 minutes on the PP over the two seasons. Cool stuff.
So he UFA'd and went to Buffalo for the ridiculous front loaded contract. Monster money. He no longer had Art Ross candidates, the Sedin twins, up to 30 goal man Burrows, Kessler threatening point-a-game and maybe most importantly a rock solid defensive partner.
Through his final season in SJ and the two years in Buffalo, his SH TOI was over two minutes a night, which is quite respectable. It really doesn't add up with the "Error-hoff" part of the discussion.
In Buffalo, he's done fine, and is a whisker below 1/2 a point a game (40 point pace). He's played big PP time at about 3:10 per game while chewing off 24 minutes a night. He's only been deployed about 1:40 a night in shorthanded situations (not a big deal).
Now, Buffalo isn't Vancouver, but Vanek chipped along very nicely last year. There's always been a few talented bodies around.
I believe he's a 1/2 a point-a-game guy, doing exactly what he's supposed to. If all the stars align once again, he could threaten nearer the 50.
I think it's fair to wonder that he's managed to wiggle some of the defensive short comings from his game, due to age and experience.
Boy, those 92 points in Vancouver sure made this guy a ton of money. That and being one of the finer UFA blueliners available in the summer of 2012.
Cody Franson, pay attention!
Anyway, value him on a what you see is what you get basis. At age 31, and in Buffalo, I don't suddenly see him exploding to new and lofty heights.