This is more of a note to myself of things to expect next time I fly Spirit Air, but I'm putting it out there in case it helps anyone else as well.
Spirit charges for bags. You probably already know this. If you don't and you fly them, you'll find out. Personally I accepted the challenge to pack with just a "personal" sized bag 16 x 14 x 12 inches (as opposed to carry-on size). The main take away is to factor baggage charges into the flight cost before booking, if it's going to be an issue. Another unusual thing-- I do like that the seats on the aircraft don't recline. While I would have liked to recline my own chair, it really nice that the person in front of me couldn't recline and crush my long legs.
FLL has a pretty inadequate capacity. Terminal 4 /Concourse H has a restaurant/bar, a Dunkin Donuts, and a newsstand. In the main concourse if you have time to leave and come back there's Sbarro and a burger joint.
The bathrooms' capacity on Concourse H is also limited, so it's actually a consideration to do business on the plane if you're connecting there from a domestic flight. You may have to wait in line to do your business at times.
If you're returning from a trip abroad, they are limited too in immigration/customs capacity. It took me two hours to get through, though I did have a bonus customs search.
It's easy to complain when flying, but it's amazing how easily we can just pop over to a foreign country. My experience with Spirit was fine; The little things here are just a reminder to myself to help maximize creature comforts next time, and there will be a next time!