I don't live in fla, but i have some pretty dark tint on my rear windows. there is more leniency here in MA with the rear windows over the front. So my rear windows are at about 5% tint (which i love, it is like limousine tint). It doesn't affect any vision, since you're never really looking out your rear windows, and on the very rear window, it actually helps dilute headlight glare from the back.

I used to have my front windows at about 15% tint, but got hefty ticket from a local cop in my town, and had to make a deal to remove it and at least put on legal tint for him to rip up the ticket. I now have 35% tint on the front, it is enough to dilute the sun, but doesn't affect vision at all. It doesn't look as "uniformed" as it used to when all windows were dark and fading to the front, but my vision is now better at night, and the cops aren't busting my chops any more.

I know Florida law is more lenient on tinting, so if I were you, I'd tint the rear windows at 5%, and put abut 15% on the front. It looks very uniformed and will block out the sun glare for sure, but it isn't overwhelmingly dark when looking out at night (the rear will be, but you dont drive from the back seat )