I might be a bit biased, because I'm currently covering #Nostr for the company. In all honesty, I wouldn't be here if I wasn't happy with them as a customer.
I'm using Relai since 2020 (when they started) and have bullied them for almost a year to give me some job. Not to earn money (I can get much better pay as social rep out of this industry), but to help them to onboard as much people to Bitcoin as possible. I believe Bitcoin is the most important thing of our lives and will always help it as much as I possibly can. Supporting a company that has similar views, is the reason why I'm here.
As for KYC, there's currently no need to present your ID or a proof or address (like when using other companies), this will change in the future due to EU regulations. For now, your info from IBAN is enough.
Happy to answer any questions you have.