Carb up meal fills my muscle up full of glycogen and usually have a great day of training when I do so. So, full, stronger, and engerized! Carb ups are usually low fat and can be very beneficial after several low carb days.
Cheat meal tastes damn good
But, honestly a cheat meal would be best used to fill cravings and be beneficial for things such as that. And yes you will feel full, but they make me want to sleep, especially if you are very low carbs!
But, both seem to really cause a shift in metabolism if you have hit a wall on a low carb diet. Like tossing more wood into the fire after depleting for several days or more.