I installed it yesterday, and it’s actually a really cool way to see stats on your email for people who like that sort of thing.  Here’s a few samples:

Communications with my boss: I can clearly see that they typically happen during the day and not in the middle of the night.  That’s a good thing.

Here’s a graph (click to make bigger) of the e-mail traffic per day: as you can see, I don’t send or receive much e-mail on the weekends.  That’s a good thing.

There’s a lot more super-cool views, but I can’t really sanitize them sufficiently to display here.  One of the cool features is the “Stay in Touch” view – it shows people that you haven’t emailed in quite some time, and it’s reminding me that there are a bunch of people I need to chat with again soon that I haven’t in a long time.  Neat stuff.