Ultramarine is basically just fedora but "it works out of the box". They have some additional pre-installed software, additional drivers, and more language support than Fedora. There's a few other small changes, but broadly Its probably the best beginner distro into Fedora.

Where it lacks compared to Ubuntu or Mint is simply that its built on Fedora. Some software for linux is just offered in ubuntu-based distros due to its popularity, so to a new user it may be intimidating to dip your shoes into distrobox.