I've set up an auto-renewing test membership using Paypal Standard, and it works fine, although if as the customer/member I try to cancel that using the link sent in the notifications that Civi sends out, this doesn't work. I understand that with Paypal Standard, although Civi can trigger the initiation of the recurring payment, Civi can't talk sensibly to Paypal about stopping that once it is set up. Does that tally with other people's mileage?
So I'm looking at Paypal's Pro service as an alternate, as from what I've read this can deal with cancellations. Is this correct, or am I better off with a different processor altogether? (Half of the problem with Paypal seems to be that they are continuously tinkering with their service offerings, and their documentation seems all over the place.)