I went to FSI @ Vero. You get what you pay for...if you can afford the extra $$$ go for it. And, does it cost more? You GET MORE than at other schools (CRM, Spin/Unusual Attitude Recovery etc.), their instructor selection process is a lot tougher than elsewhere (do you want an instructor who got their CFI ratings in a couple of weeks or over several months of thorough training?), the maintenance and plane availability is first class and the facilities are excellent. And, if you get a job right out of school with only your commercial/instrument/multi because FSI is on your resume it is worth the $$$ right?
FSI has a formidable (and deserved) reputation in the industry and that alone is worth a couple of dollars!
Just my opinion...