IMHO, there isn't any good coffee inside MGM. (I prefer to drink Caribou or Starbucks, so you know my taste, which may not be the same as yours).
The Hawaian pressed pot coffee at Kona and the African pressed pot coffee at BOMA or JIKO is very good. You can get Starbucks at Tubbi's in the Dolphin.
I bring my own and brew it in the room in the morning. Don't much care for Disney coffee.
Disney has a contract with Nestle and with very few exceptions (believe I mentioned them all above, LOL), that's what you get. Last time I checked, most of the coffee is made with some type of coffee "syrup".
If you just want caffeine, aren't particular about your coffee, or are just plain desparate, LOL, the Disney coffee will do just fine. JMHO. YMMV.
Best wishes -