What I find particularly intriguing is the ability to toggle payment, withdrawal, and online payment on and off individually from within the app and website. This supposedly happens in real-time, so you could turn withdrawal on, withdraw some money, and turn it off immediately afterwards. This should be quite useful to limit fraud.
Unfortunately, there's no support for HBCI/FinTS or even CSV exports, so I cannot import any transactions from there into my hledger journal. If that comes one day, I might be able to switch "completely" (sorry, Sparkasse - I love you, but I need a credit card).