I haven't offroaded in the X - not quite brave enough yet

, but have offroaded many times in my old 4x4 stock Rodeo. With regard to sand, the other posters are right, it depends on what kind. The X shouldn't have any problems on firmer packed sands, but with its weight would be in trouble in soft sands, especially in dune situations - it doesn't matter if it's on a beach or on the beach.
On beaches and river crossings, you will have to be especially careful of sand that looks firm and dry, but it's actually wet and spongy underneath - like on a sunny day after heavy rains - the top is dry, the bottom isn't. I've stuck the Rodeo - a tough truck - a couple of times before I learned my lessons.