The Witcher 3 had a bit of a rough launch when it came to UI. When it originally launched, the community was up in arms with it's "unusable" UI. The game was great but navigating menus was a chore. CD Projekt Red quickly patched the game with updated UI. I have only played the new UI and I have to say that it wasn't bad. I played with a controller and quickly got the hang of it. Now, I can safely say that The Witcher 3 is one of my favorite games of all-time.
It's been a while since I played but I don't remember any glaring issues with the UI. It was tedious to have to press Start then A to get to the Map or any other Menu but that's the price you pay for playing on the couch. There's a lot of "There-if-you-need-it" UI always on the screen. Stuff like your button controls, time of day, adrenaline bar, and step counter to objective. These probably could have been moved to another spot because if I forgot any important button (like using my Witcher Signs) I had to go into the keybindings to figure it out anyways.