I live in Florida, and I dislike tint. As far as temperatures inside the car, tint is kinda like feeding a tic tac to a whale.... "Wow, now that I've got black limo tint on the car, it only gets to 200 degrees instead of 220 degrees!!" LOL!! It's a futile attempt to counter an unbeatable foe. Either way, dark tint or not, it gets as hot as the hinges of hell inside any car during a Florida summer, so I don't waste my time with the tint. The reasons I don't like it are relatively silly, but nonetheless, important to me.
First, it cheapens the look of any car IMO. Tinting the windows is the first thing any teenager or Camaro owner does to their car when they buy it. When I see dark tint on a premium vehicle, I find that I react to it the same way I do aftermarket spoilers and bumper stickers.
Secondly, dark tinted windows scream "used car" to me. Don't ask me why. I know that every car is a used car once you use it, I just like the look of the factory window treatment.
Lastly, I like a bright interior. Sitting in a dark tinted vehicle is like sitting in a dungeon sometimes.
You asked for opinions, so... those are mine!!
No offense intended to the tint lovers out there. I tinted everything I owned up 'till my late 20's. Now at 37 I'm just a grumpy old fogey I suppose.