I can't tell if my traffic is affected as I just gained a lot of traffic back from the Penguin update. I meant to say though, as atlantic87 said, the positions that whoever it is at google is checking are significantly better than I see them. For my main phrase I am #12 and my stats report the googler at #2. Maybe just their personalisation?
I am not just seeing this for 1 keyword there is at least 1 more that is regularly hit as well.