Speaking as a non-merchant, I'm curious. What's the most painful thing that Stripe took care of?

Waiting weeks for getting your merchant account setup. This usually involved faxing your ID and filling out boatloads of forms.

I have yet to implement Stripe but PayPal's options without a monthly fee are downright goofy (and PayPal is the only other processor to have a no-monthly-fee option in Canada). "Buy now" buttons and IPN... eww.

Okay, now that I've officially implemented Stripe the official answer is dev time. PayPal took days to get a full solution implented (start to finish). Stripe took on the order of three to five hours. I can already tell maintenance will be almost non-existent in comparison and user experience is way, way better.

Replacing Paypal?