The Braintree API wasn't too hard hard to integrate with, but their web interface for configuration and management is pretty ugly and unintuitive. I especially dislike how they share test instances between multiple customers. Their customer support is really responsive and helpful though.
I wrote a quick Rails plugin to interface with the recurring payments with Braintree. It doesn't implement all or their API's, but it's enough to handle monthly recurring billing for Outspokes. I pushed it up to github in case anyone finds it useful. Let me know if anything's confusing about it. I'll polish it up when I have more free time.