Just installed (been looking for something like this for a while, and nothing worked yet...) and while twitoaster.com says I'm set up, it doesn't look like it synced with my comment database just yet.
Not totally surprising, I'm sure it's a cron or something to not overwhelm APIs and server calls. But. Can a 'force sync' or something be implemented on setup so you can get started and see how it works?
I'm going to leave it in for a week and see what happens :)