I installed it. It's so nonintrusive that there was no reason not to.
It would be nice with a log -- just a simple text-file -- that records at least the IP and time stamps. Not only is such a log necessary if a legitimate user complains that he hasn't received a mail. I'm also unable to vote on your product if I don't know what it's doing.
Another feature I miss -- but this is probably outside your scope -- is when a bot answers our human verification questions. It would be nice to know WHICH question the bot has successfully answered.