I currently have an I2. I previously had an X2 that I bought in large part to use on the beach. I used it in Ocean City, Maryland. The sand is very loose and deep. They use beach cleaning machines every day during the summer. Riding close to the beach where the sand was damp or wet was no problem at all. In the loose sand, I would be going along just fine, and it suddenly would throw me like a bucking bronco. The biggest problem was that it gave no warning that it was about to happen. Just riding along as a happy camper and then suddenly had a face full of sand.
I got rid of the X2 because it was difficult to use inside. Rick from Segway of Corvallis hooked me up with a new I2. I couldn't be happier with the machine.