Mantine is brilliant, I can build anything in it quickly and then extend it or completely customize the theme or individual components, but there is a learning curve. I would not call it a giant learning curve.

I love Mantine. It’s easy to use, full featured with lots of components and helpers, and yet if you need to, you can use it headless and customise it too (I’ve never bothered though; I did add my own additional spacing/sizing options via the theme support though)