In general, in Paypal, we have several ways to setup a payment gateway.
I would like to hear what would be the better way.
i.e. in membership pro, we have available setting up Paypal with email or with IPN
The case should be that recurring payments should be possible. That customers have to verify that recurring payment is actually no problem and perhaps even good, as they themselves have to give their OK for another payment before they get fined for late payments because they did not cancel early enough i.e. one month before - like it is very usual in Germany by Hosting providers etc.
Setting up IPN is always a headache and a big one when doing it with lots of sites and lots of plugins. On the other hand, the wp mu dev plugin pro sites does not provide the way to set it up using the email address. It looks as there is an inconsistency inside all those wp mu dev plugins provide PayPal gateway setups.
What are your experiences and what would you recommend, what are your solutions to handle multiple sites and multiple plugins.
Thanks in advance