Choosing between CI3 and CI4 for custom CMS

What CI3 can do CI4 can do much more better.
It your choice.

As I'm starting getting into it, my thoughts become more clear. CI4 seems to be a neat successor to CI3 but I'm not proficient and it will take some time for that. Trying to build in CI4 will result in something I don't put my best utilization of the framework in.

As an example, my first CI3 projects were messy as I was trying to get around with the framework. Now from my experience, I know each time what exactly will work best for me. It's like being driven by the framework at first and then learning to drive the it yourself.

Is that kind of feeling relevant? I'm thinking of building stuff for fun in CI4 that I don't care about before using it for real production.