You'd have a much harder time finding something bad about FSI. Some people will try to tell you that the negatives are:
1.) the length of the wait list to instruct there...but don't pick a school based solely on whether they say they will hire you...thats rediculous- tons of things can happen between the time you start, and the time you're ready to get a job. Pick your school based on quality.
2.) The cost- Sure its not cheap, but none of the big flight schools are. The prices they quote are very realistic, and many people finish under budget if they work hard (myself included). If you have your heart set on one of the big academies, then dont let a grand or two here and there make your decision- they're all about the same price when its all said and done. Oh yeah, and you don't have to pay them one cent up front...so no getting screwed ATA-style. Once again, go for quality.
Some positives:
The planes, are in excellent shape. When I left they still had a few of the older Seminoles (not sure if they still do or not) that they used for initial multi training. All the rest of the Seminoles are about a year old. The Cadets and the Arrows are all in excellent shape, as the maintenance is second to none. If you've got a squawk, they'll come out on a golf cart and fix it...if its going to take a while, they'll assign you a new plane.
Your training would include Spatial Disorientation training, Crew Resource Management, and Upset Recover/Spin Training....all of which are awesome- especially the URT/Spins.
The CFI program there, while intense and somewhat lengthy, is second to none. To be honest though, the CFII program is nothing spectacular...just a quick ground school to review IFR procedures, then a few flights. You could probably do it just as well and cheaper elsewhere.
I'll be the first to plug FSI, but also to say go look at some other schools too, then make your decision. Good luck!