We use this for our crowdfunding platform, EquityEats, and have been happy with their support. Anyone that has dealt with ACH knows that it's a pain, but SynapsePay makes it easy - and at a flat rate of 25 cents a transaction!
They started in Memphis, moved to SF a while back, and are making lots of progress!
I also release their initial ruby client for their API (which I still use and maintain although they've since released official clients): https://github.com/milesmatthias...
StartupCTO.io 22 – Jud Valeski