My husband and I both did this a few years back and had a lot of success with it.
The negative, it is hard to maintain.
The reason I say this is because when you go to Mexico, will you eat small portions of protein every 2 hours?? Probably not, so while you may lose the weight before the big day and honeymoon, I feel you will gain it all back before you return.
It is an excellent program, and one I stayed on for about 18 months before I just couldn't look at another boiled egg, slice of ham, chicken, turkey, meat again for a while!! I found there were too many 'unallowed' foods on the list, making it very difficult for me (as a mother) to maintain while I was out and about (shopping, sports for kids etc).
All this being said, I wish you the best of luck. I am NOT a critic to this system, for it truely does work, while you are on it, so knock yourself out and all the best for your wedding and honeymoon!!