Spirit is as good as any other airline and in some cases, better than some majors. But, as already said, you will pay for seat, checked luggage and carry on luggage. 1 personal item (stored under the seat) is free.
They have recently changed their web site so that all charges are presented to you before the final purchase. That was my only beef with them in the past.
They fly out of the newest terminal, the North Terminal. There are many airport hotels, parking and shuttles in the area. the airport itself is very easy to get to.
Security lines are not usually long and always rather quick to process. One side of security was closed a few weeks ago as they were installin new x-ray equipment. It may be open now but not sure.
David
David