I can't really imagine a stroller that would go through sand. Do you mean hard, wet sand or actually sandy dry sand? I have never tried to run with a stroller on the beach, but I have never had luck even pushing a stroller down to the water.
We have the BOB Ironman that I've used on the beach on the Oregon Coast. But the beach there is very flat and hard packed so I don't know how it handles on softer sand.
Re: Question for Runners