Inconsistent and slow
First, there's only a link to leave a trustpilot review after positive customer service feedback. If they know you are unhappy, the link is not provided. Smart move to try to get more positive reviews than negative ones.
I have an account with them for years and once I wanted to open a n26 savings, they locked my account and asked me to go through the identification process again,  which I did, with the same document that I used to open my account and a renewed residence permit in the exact same format as the previous one.  However,  their identity partner only accepts residence permits in an ID card format (!), even though the document is/ has exactly the same legal validity. I  had to contact their customer support several times and file a complaint, but still nothing, my account remains unduly locked and I only get procrastinating answers, apart from the messages that they send internally via their system and I cannot read because (REMEMBER ?) my access is locked. Next step is hope for BAFIN to help me with this.