I've had more than my share of 4+ hours (up to 8+... all AA flights) of layovers in Miami the last 10 years. I can't think of worse places. (My nickname for MIA is hell.) I purposely booked to AVOID the 4 hour layover. AA took that choice from me, again. Not thrilled. The later arrival really irks me. I can wile away hours w/ reading but would much rather be on my way to Jamaica.