Automatic subscription options as I understand it: Credit Card via Paypal businessCredit card via Stripe/SSLCredit card via alternative payment systemAll those ill avoid "recurring invoice reminder to renew". That is as far as I got with my investigations as my users do not want to use credit cards. Hope that helps.
We ended up with some users staying on the old 3.8.x Subscription system using the gateway. Of the new subscribers since moving to IPS 4.xx, as moving to SSL for Stripe is not valid for us, we're got users switching to direct bank transfer to my personal bank account, and others using the dire "recurring invoice reminder to renew" service. Nobody is impressed with the new system at all, and I wish we could have stayed with the old system. I anticipate subscription take up since moving to IPS4 to be maybe reduced by 80%. Everyone loved the previous system of automatic subscription renewals via PayPal, nobody likes the new "recurring invoice reminder to renew" service, and none of my users want to go the credit card route. You can use the PayPal credit card system of course for a monthly fee if you upgrade to a business account, not viable for us either. If I had known about this with IPS4 we would not have uplifted to the new software. The response I get from IPS is that this is all down to PayPal changing APIs, and they have no choice. However has the old 3.8x subscription system suddenly stopped working, I think not! If I did not have a very close relationship with my small user pool we'd be shut down by now due to lack of finance.