1) We started with Braintree. We had to implement their SDK, and then we were charging PayPal and Credit Cards. Each transaction had to be accounted by us, we had to specify how much VAT. In Europe it's tricky because you have to charge VAT-MOSS based on which country customer is from (eg. 20% for UK, 23% for Poland). So accounting was a nightmare. 2) Then we switched to Stripe (new sdk to implement) and PayPal separatelly (another integration to support). Same crap as with Braintree. We only switched because Braintree kicked us out. A lot of developer work wasted to support paypal separatelly etc. Even more work for fixing PayPal's constant CSV changes and API changes to integrate with accounting. Then there was still some issue which I had to manually fix in accounting. Again: nightmare.
3) Then comes our saviour Paddle. One SDK to implement (so like implementing only Stripe) but you get all different features, like nationalized prices, one big invoice at the end of the month with VAT calculated by them, abandon baskets recovery etc and much more.
5% but hours saved in productivity and accouning. It was and still is worth it and I don't want to ever switch back.
Thanks to Paddle for keeping my mind sane :)
PS. If anyone is interested we use it at FreeYourMusic.com