I remember starting a thread about it a while ago and it was debunked by nutritionally trained experts and geniuses who know everything about anything even with their heads firmly wedged into the sand (plenty of these experts on this forum). If I recall correctly Bazza screamed the loudest, without even having looked into it, or understanding the science behind it.
I remember researching it extensively over several weeks, listening/reading all the pro's and con's I could find and then proceeded to give it a run myself for a while, so I could make an EDUCATED decision about it, rather than the scared child like process where I close my eyes, block my ears and scream 'no no it's not real, no no it's not real, no no it's not real' over and over whilst rocking back and fourth hiding in the closet hoping for it to go away approach many here employ to nutritional advances/discoveries/theories etc and then proclaim to know everything without ever having spend a single minute educating them selves.
Anyway it depends how you use it, this style coffee concoction is not magic as you probably already know, and it works best with an intermitted fasting style eating approach, I think it's benefits would be somewhat lost with a bro style eat six meals a day approach, as the coffee concoction is supposed to replace a meal, fill you up/make you feel not hungry, while providing the body with enough energy to carry on it's daily activities without eating any food for as long as possible. It is not to give you some sort of magical energy boost, but just provide energy without spiking insulin levels sky high and upsetting the fat loss properties of intermitted fasting.
So the idea is get up stall eating, when you get hungry have your concoction, it will provide energy(butter/MCT Oil) with a caffeine boost (same as a normal coffee), some people suggest adding a small amount of WPI/WPC, may be 5 grams or so from memory.
I would not buy into the carp about using/buying coffee beans 'mouth picked by amazon virgins on a full moon', I think just normal instant coffee or plunger brewed coffee will do the job just fine. I used the Nescafe Green Coffee instant powder, and I tried coconut oil as suggested by some but hated the taste. So I just used Natural unsalted butter and MCT Oil bought from BN. Used to make up a batch and drink it in my thermo cup on the way to work, never felt hungry till about lunch time or later, if I had a second mug around 11am it would take me through till dinner easy enough without feeling hungry.
MY PERSONAL CONCLUSION:
I did not mind the taste of it with MCT oil rather than coconut oil, and was quite looking forward to my daily concoction, it easily reduced my daily food intake without losing energy or feeling lethargic during the day, which I find happens to me when I reduce food intake too much, it also greatly reduced cravings to snack during the day.
Personally I would not bother with it unless you are following an intermitted fasting style diet and looking to lose some body fat. As a training energy booster it has about the same effect as a cup of coffee (as that is what essentially it is). The MCT/Butter effect only come into play if you are fasting.