I have had Authorship set up for a few months, here are a few things I have noticed:
1- My traffic has increased by 300%. Is all of this attributable to Authorship? No, but I believe a big portion of it is.
2- Don't link to your G+ profile in your lawnsite signature or your threads will be attributed to you and show up when someone clicks on "More by Ben Bowen".
Check out this article for more: