Curves is great for people just starting out, or people like me that have so much to lose who would feel more comfortable in a controlled environnment (that's code for they're for women only!
) There is both good and bad Curves locations. I belonged to Curves back in 2003-2004 and I absolutely loved it. But once my office moved I had to move my membership to one closer to home and I absolutely hated it! You need to check out the franchise itself - it's the owners/managers and the people that work there that make it worthwhile. At my first location they were always mixing up the music and having ongoing contests to keep you from noticing how repeatitive the circuit was and they had at least one of every piece of equipment. The trainers were always in the center of the circuit pushing, motivating and leading the members. At the second location I never saw anything but the top of the "trainers" heads as they played on the computer and chatted on the phone. They never greeted anyone coming in or going. They didn't have all the equipment and their hours weren't as good as the other location.
But that said - in my option you have already surpassed what Curves could offer for you. By that I mean you have already lost a significate amount of weight and you've already been exercising on your own. For the same amount or a little bit more you could get a membership at a regular gym that offers classes and has a swimming pool along with the other exercise machines.
Oh - I forgot about part of your original post! As far as the Curves Diet, only a few (at the most 10-15 members) followed the Curves diet. Everyone else was doing their own thing.