I haven't used Start9 yet, but perusing their app list was a little disappointing. The goal for THIS build is for the simplest possible setup and operation for a non-techy person. My guess is that Umbrel is going to be the most user-friendly UI once it's up and running. But will give Start9 a try, ...

I would have gone with Start9 if they supported samourai dojo. Was kindof a deal breaker for me.