I wouldn't call MIA/FLL convenient, but its doable for a short trip where you just want to sit on the beach at a nearby hotel. In some ways, especially in MIA, a car is a pain with parking, etc. Thanks for the tips re: Denver. It'd be a short trip so I can probably pick and choose things that are conveniently located. I also have a friend in the area, so I think a lot of us are leaning on friends around the country until rental car prices return back to normal!