It's hard to figure out what it can do. Everywhere is their branding. As I understand they just send payment receipts, but no invoices.

I'd like to offer a free trial. While they have support for this, a user needs to enter his credit card right at sign up for trials to work.

So in the end I have to build a hybrid solution where my system gets tied to theirs. Still I don't have full control over all e-mails that are sent to the user. I'm not 100% happy, but better than not charging money.