I used Ubuntu for over 10 years. I loved it. But Canonical does have a lot of baggage. Plus, I wanted to go to the source. So that's why I use Debian. I'd still advise a new user to go for Mint if they loved the Windows UI or Ubuntu if they hated it. If you use and love Mint, I don't think anyone would criticize you for continuing to use it. If you use and love Ubuntu, I'd say Debian is a very easy next step.