The _buyer_ experience with Apple's IAP is mostly good, but I would argue that the developer experience is downright horrible. Working with subscriptions and IAP receipts is clunky. You can only use one of about 100 SKUs, which makes it difficult to offer discounts and customized pricing at the higher price tiers, where the gaps between amounts are quite large. Until recently, it wasn't even possible for developers to issue refunds!
Even if Stripe charged 30%, I would choose them every time over Apple's IAP.