The information presented in the Sidebar is interesting enough to keep me from disabling it. I do, however have a complaint. And it has to do with the email alert portion of the Sidebar:
It does not do spam filtering. It's true that there is a way to add filters by hand. But that's so inadequate, especially considering that I have trained my Thunderbird spam filter to do a pretty good job.
(I have to send myself several test emails just so that I can take a screenshot that won't embarrass everybody.)