If not fitted then velcro is the way to go.

True, once you have a velcro hat adjusted correctly it will stay there, but the velcro adjustment is the absolute hardestest to get adjusted correctly. And then if your hair grows, or you cut it, the adjustment is wrong.

I like the sliding belt buckle, much easier to adjust, and I've never seen one come out of adjustment but I can see that it could.

The stretch hats would be nice if they were made in S, M, L, but all I've seen is S/M, M/L, which neither is right for me. It seems they go by how far it will stretch, and forget about the comfort when it is stretched as far as it will go.

The plastic knobs thru a hole is ok when I have hair, but when my hair is cut short I can feel the plastic, don't like it.

I thought those stretch hats came in a L/XL size too.  But, I do like the idea of having sizes like S, M, L, XL.