What Kind of Performance Considerations Do Libraries Have?

There's a penalty for having abstract api, right? You have this penalty of transferring between your data models. If you write purpose built software for a purpose built format, you're going to beat it. The bargain there is that, as a consumer of the content, you don't have to worry about all those intricacies. But if you need performance and you need to manage your system very precisely so that you know what's going on all the time, you're just going to do much better developing and controlling that yourself.