I think it all depends what bodytype you have, if you have a fast metaboilism or slow. I have a slow and I love the method. I tend to gain fat very fast so I eat very clean and never go above 1000cals over my maintenance calorie intake on the bulk. For me a cutting phase of 10 days are enough just -500 from my maintenance C. intake. The diet plan works, for some better than others. A friend of mine have been on the ABCDE diet for a very long time, and he has done pnice improvement. He is an ectomorf so itäs very hard for him to gain weigth. For him a more "unclean" diet are better than a clean one, compared to the one I use at times.
Try the diet, if 12-14 days bulk followed by 12-14 days cutting doesn't work very good and you gain to much fat, or don't gain at all, then change your diet. There is no exact plan, there never is. Only a frame to help you on the way. I tried the 5 days B - 5 days C and it worked better for my bodytype.