Hi there, I found myself with the same dilemma, I had tried WW before but only did it for a few months, never tried SW. The reason that I chose RC was primarily that for the same price as the aforementioned you atually can attend a free fitness class and for me it is about toning, fitness and shape along with losing pounds.
The other thing I like about RC is that it is not a diet really but a new way of eating ( a set amount of calories and all foods to be within the 5% fat per 100g rule) I know that I need to maintain this way of life, with WW I found there was too much freedom and the 'eat as much free food as you want ' ethos of SW did not sit comfortably with me as portion control is a problem (greedyguts !!!)
I am no way dismissing WW or SW as it is horses for courses and I have read about all the success' that are posted on here daily, in fact a work colleague has lost as much as I have without any exercise ( I do a lot !!) on WW online so it is merely what works for you.
I personally could not survive on a VLCD but a friend has lost 5 stone 4lb since the 1st of Jan on Cambridge.
I would do some research and see what appeals, good luck xx