Yes, there is a noticeable difference between the 2 bits. With the Full Cheek, I like to think of it like this...essentially puts up a "wall" on the opposite side that your trying to go. So your turning Aires right, and it's going to be like you placing a full hand right alongside the left side of his muzzle and gently pushing his face in that direction. So your pushing from the left side, while pulling from the right.
I hope that makes sense. It was explained to be about 10 years ago and my trainer is much better at explaining things then me. She started my first horse in a Full Cheek because he didn't have a lot of flex and bend in him.
"The greatest pleasure of a dog is that you may make a fool of yourself with
him and not only will he not scold you, but he will make a fool of himself too."