I have been a member of Fit Factory for close to 2 years.
Pros: you will not get a work out like this anywhere else. If you have an aggressive fitness goal or want to push yourself this is the place for you. I thought I was in decent shape when I started classes at Fit Factory and quickly realized that was not the case. In the first 6 months I lost close to 10 lbs only coming 2-3 times per week. I like that the classes are always different (never boring) and some classes are in the park near the studio which is a lot of fun.
Cons: The studio is great, but the evening classes are often quite crowded and hot. I prefer being outside in the nicer weather so there's more space.