I have actually been doing this for 17 years (yes, I started when I was 15), and as I mentioned in another post, I always thought it was my own "thing" until I came across this website.
As with you, my weight has gone up and down over the years as my discipline has waned and my activity levels have varied, and I now consider this method to be a "lifetime weight management" system than merely a means of weight loss. I don't remember how much I weighed when I started, but I did have some childhood "chubbiness" to work off, due to a condition that had restricted excercise. Apparently to my 15-year old mind I weighed too much

, but it was probably around 115-120 lbs. I am 5'2" now, and may have been a little shorter then (I think I stopped gaining height around then or shortly after). Now I weigh probably between 125-130 lbs. - ironically, but I have been as low as 108 to my recollection, maybe lower. I do recall losing weight within a few months of starting, to the point that I had quite "the bod" in high school - although of course at the time I could not lose enough, but I would almost kill now to have the body I had then.
Munchies and finger food are my downfall, so there has always been the struggle not to nibble on weekdays. My appetite skyrockets when I'm under stress, and my motivation gets blown every time I go on vacation. I have recently renewed my determination and hope to get back down to 110-115 lbs, which seems reasonable for a person of my height and bone frame. And I am also incorporating another method which will hopefully help with hunger pangs (the Shangri-la Diet, which I may bring up in another post; you can Google it to find out how it works).
My method has been slightly different, even though the basic idea is the same. I've always restricted calories and tried to make what I did eat healthy. I didn't always cut out sugar; dessert and "sweets" were no-no's, but I would put jelly on toast and eat sweetened yogurt. "Low-fat" was the mantra while I grew up, and that's the mindset I'm still in - the Covert Bailey school of "eat-less-fat-to-be-less-fat". I think it's still a good idea, since less fat means I get to eat more food for the same calories, but in recent years I eat peanut butter and avocado when I would never have touched them before. A while back I tried cutting out ALL refined sugar - no sweetened cereal, no jelly, no sugar in the tea or coffee; only "naturally" sweet things like fruit or honey (except on S days, of course). I lost weight, but the effect waned after a few months, either because my body got wise to it or because I didn't stick to it well enough after awhile. Looking back, it may have been mostly water weight, since water accompanies carbs, but I think it's worth a try again.
In short, to the "NoS" rules I have added 1)low-fat, 2)lots of fruits and veggies, and 3)don't eat supper too late. I don't count calories anymore, but after all this time I know how "full" I should feel before I've eaten too much. I also started running when I was 15, and have done some form of excercise (swimming, biking, aerobics, weight-lifting, and now cardio-kickboxing) ever since.
Now it's my turn to ramble.

I hope I've answered your question(s). Even as a "seasoned veteran" it's comforting for me to know that other people see S-days as a necessary component of the whole system, whereas an "outsider" would immediately discard them as a wrench-in-the-works. I hope I haven't discouraged you, having been on this method for so long - you really can lose a fair amount of weight in a reasonable time; you just have to stay disciplined, and actively keep it off after you lose it. I'm glad you're so excited - nothing is as uplifting as hope. Happy losing!