Pros
The main advantage of Equinox is the constant exposure to discounted educational opportunities that also count for CECs towards certification renewal. Although Equinox supports many dubious ventures and not all educators are of highest quality, enough are that it's quite worthwhile. You'll also meet and work with some really great people. The "free membership" perk is overrated. Equinox is not a good place for someone serious about getting stronger and fitter to work out. It's workable, but not good.
Cons
It's difficult to make a living wage in this city working for Equinox. They pay very poorly, yet expect a lot of work from you - and no work/life balance. The managers are mostly incompetent and unwilling to actually manage. Their policies prove that they don't care for the well being of their employees, and anyone below the level of General Manager is pretty much expendable. The worst part, though, is their claiming of the moral high ground for being the company that dedicates the most resources to education and investing in their employees. To have attained top level trainer status, you're not once required to demonstrate proficiency in actually coaching exercises properly. Taking an online multiple choice exam about Target Heart Rates doesn't mean you can SAFELY and properly teach someone how to squat, or do a kettlebell swing, or any other movement. The managers often don't know proper form and technique either, so they're in no position to assess their staff! The other gyms (NYSC, NYHRC, Crunch, etc..) are no better and probably worse, but they don't make the claims Equinox does about investing in their employees education. The clubs are also too crowded. I always felt that someone paying thousands of dollars for personal training shouldn't have to wait for equipment, or alter their planned workout, because the gym is crowded with snobs unwilling to let people work in with them. The company overall is more concerned with this month's numbers than anything else. That tells you all you need to know.