Another long term low carber here, I too fall off the wagnon every now and then for a week or so and then jump straight back on. Its become a way of life and the only way to lose bodyfat for me. Mines not atkins though, its just extra low/healthy carb and high protien - essentially a bodybuilders diet. Best of luck!
Buda - did South Beach (very similar) and had good results. It does take some willpower but the results are much quicker than regular low calorie diets. My main struggle was not having wine or chocolate - but it didn't bother me giving up the potatoes/pasta/rice etc. My daily diet consisted of Bacon and eggs for brekkie, Tuna/Ham/turkey salad for lunch and steak/chicken etc with roasted mediteranean veg for dinner. Making a big bowl of chilli was good - you can even have sour cream on it!
BCIW - I did it with ediets online abut 4 years ago and lost 2 stone. Felt great on it. I don't limit my veg intake or weigh anything.
Am planning the full 2 week induction/bootcamp (yikes!) with no alcohol. Will then have bacardi and diet coke as my tipple. Have just done a menu plan for the week. DH is doing it too which makes life easier. Will do another menu plan and then alternate them.