As a customer of N26 and Natwest/Barclays I feel that N26 in my experience has won in every category.

Superior support when I need it on demand, the tech and apps seems solid, intuitive analysis and usage, the ability to have multiple sub-accounts and the ability to create rules to route money between them.

Natwest in particular seem stuck in the past, I cannot count the amount of times I've opted in for digital communication only and always continued to get letters to which I can never get through to support.