As many others have said go with the school that has the best instructor. The system isn't nearly as important as having a good teacher.
Visit the schools and ask questions. If you can observe a few classes, focus on the intermediate to advanced students. Watch how they move and perform. The beginners in a class are usually a mixed bag, but the people that have been with a teacher for a while will show you a lot about that instructor. See if their stances are solid, how smooth their footwork is, if they generate good power behind their punches and kicks, and if you get the chance, how well they spar.
Don't concern yourself too much about how the teacher moves. You aren't hiring a bodyguard or stuntman. Look at the students he has trained for awhile and you'll see the fruits of his teaching ability.
Observe also the atmosphere of the school and see if it is a place that you would be comfortable training. The best school and teacher in the world won't do anything for you if it isn't a place that you want to go. I make a list of things I look for before I go and evaluate the school to see how closely it matches what I am looking for. I like a relaxed atmosphere, no contracts, medium to heavy contact in sparring(headgear though, I've had a skull fracture so I am more carefull about contact than when I was younger), a good conditioning element during the class sessions, limited amounts of transplanted Japanese/Chinese culture, and clean facilities.
However your list forms up, make sure that the school you choose matches as closely as possible to it.
If you keep the above in mind you will find a school that fits you and that you will have a good experience with irrespective of the system.
Hope this helps a bit,
Mark