I definitely think it has merit. Dan Duchaine's Isocaloric diet is designed to maintain relatively low insulin levels throughout the day and is primarily a weight loss diet. The lower insulin levels allows your body to maintain fat burning throughout the day. The massive eating diet is designed as a bulking diet with periods of high and low insulin levels. The higher insulin levels will help promote muscle growth while the periods of low insulin allow your body to burn fat. You're attempting nutrient partitioning. Which isn't too far fetched considering eating six to eight meals a day certainly has an effect.
When using Massive Eating to diet I generally eat my prot/carb meals in the morning/early afternoon and Prot/fat in the late afternoon/evening. However, if training in the afternoon I still have most post workout nutrition. The reason is that insulin sensitivity declines in the afternoon and is highest in the morning, which is why Duchaine recommended not eating fruit after noon when dieting. Remember, the massive eating diet for fat loss is designed to take months to remove the fat unlike intense dieting.
I highly recommend everyone give it a try. I've been doing it for about six months alternating bulking/dieting/maintenance every two weeks. Worst case scenario, it won't work but at least you'll know it's not the diet for you. Best case scenario, you'll be leaner and bigger than you were last year, which I am.