Getting things setup is WAY too complicated. There are so many options it's overwhelming, and the places you have to click or navigate to in order to activate some of those options are so far from intuitive that it's not in the same city, let alone ballpark.
They have recently cleaned up their interface, and from what I've seen it looks a lot less clunky than it used to, but I haven't yet been able to tell if the entire UX has been overhauled to work better than before.
I was using Stripe as a payment processor, integrated with Xero for accounting. Stripe didn't offer a way to do recurring billing, and Xero doesn't actually process payments, so their recurring billing is nothing more than sending an invoice. I wanted a way to automatically bill someone every month.
Rerun allowed that.