As a member for the past few years of Equinox with a membership that allows me to use them across the country, let me provide a little perspective on the entire chain:
(1) Near my home: Living across the street from the 76th Street Equinox on the Upper West Side in Manhattan, the convenience factor for me is high. As for crowding, its not worse than the Reebok/Sports Club LA that is 10 blocks away, which is to say that there is generally no waiting for cardio equipment and people are usually friendly about alternating on weight machines if necessary.
(2) Around NYC: Equinox is considered to be slightly lesser than Sports Club LA, but certainly of a higher quality than the ubiquitous New York Sports Club (equivalent to 24 Hour Fitness in price/quality). The equipment is quickly fixed at Equinox and the locker rooms are reasonably clean. Equinox likes to claim their bathrooms are cleaner than the bathrooms of most members (and they have studies to back it up), but I for one am more comfortable with my own dirt than that generated by other people. Be warned that only some of them have pools, if that's an amenity you want.
(3) In San Francisco: I've used the facility in the old Pacific Stock Exchange building numerous times. The facility is extremely unique given its historic status. The gym is two main floors that are very open with gigantic ceilings. The basement holds the lockerrooms inside of the former vaults and a small pool. The place is definitely the nicest Equinox I've seen, so if you don't like this one, forget signing up.
(4) Hollywood: The Sunset Boulevard location is prime, though the parking garage is a pain. Then again, being from Manhattan, driving is a pain to me. The facility is also nice and new, but seems to have a wierd distribution of members. This may be a function of Los Angeles, but it was full of young, healthy people seemingly hanging out at 3pm midweek in workout clothes, but not working out very hard. This was a scene more than gym, though the equipment was readily available.
(5) Chicago: I've been to suburban and downtown locations. These are the only Equinox locations that seem to be much heavier on older, less fit members. That may be a function of suburban locations, versus the others I've visited which were all urban. However, the trainers actually appeared out-of-shape, which is a scary sign. However, the equipment was new and there was plenty of space. The pool in the suburbs was the largest I'd seen in an Equinox, which figures, given the land is the cheapest out there.
Overall, I've found Equinox is good at keeping their equipment fairly refreshed and the staff is generally friendly and non-intrusive. Given that their price point in NYC is between the highest-end and the average-priced gyms, its a good value from my standpoint.
-MJ