let's say I run a simple race attack (say in a restaurant). I transfer BTC to the restaurant but seconds before (or after) I send the very same coins to myself. To make this deal more likely for myself I assign a much higher fee to the transaction loop for myself. How common are such race attacks? I don't think the restaurant can wait like 6 blocks before they accept my payment. I would be most happy if you can point me to papers, stats, etc. Or is there a big gap in my logic?
Or is there a big gap in my logic?
Your logic is right, it is just that no decent service will accept a payment unless 1, 3 or even 6 block confirmation.
How common are such race attacks
Not common at all, but if the services or the person is forced to accept unconfirmed block, here is a link with information about how to better perform and how to defend against a race attack.
I don't think the restaurant can wait like 6 blocks before they accept my payment
You are right, and the fact that you have to wait ~30 minutes can be a problem for mass adoption, this is one of the reason there is a project called the lightning network build on top of bitcoin trying to solve this and other major things by rendering transaction instantaneous while keeping the security, you can read more here: https://lightning.network/