For me the problem is less the UI but weird bugs / unimplemented cases in its modeling kernel. Some lofts and tubes just refuse to work for no apparent (to me, a non-expert in CAD) reason. Even worse, simple fillets sometimes don't work as expected on moderately complicated bodies. Maybe if you're an expert you can avoid these case, but it's extremely frustrating to spend several hours successfully modeling the general shape only to be unable to apply simple dress-up features.

I'd really like to use it and master it further, but CAD is not something I need often, and in F360 any geometry I've needed just works.