At SerpApi.com, we are currently using Stripe subscriptions. But I feel it's suboptimal. We have a lot of code duplication to support sync of subs between Stripe and our app, upgrading/downgrading is no easy tasks, and no PayPal support.

Thinking of rolling our own. Just capturing a token from Stripe and PayPal and a cron to charge customers. Wary about loosing auto-update credit cards and anti-churn email feature from Stripe though.