I see that some have adjustable genoa car and some have a floating genoa car. Which one is better?

Also, for the adjustable who would be the best? Harken is common but expensive. Are the later hulls Lewmar? Has anyone used garhauer? They seem inexpensive and have heard good things about them.

On the floating system, I have looked at the pictures on the website but there are quite a few blocks to make it work. Does anyone have a simple design?

Thanks for the help!!