Yes I have. The Sand Stream ability is in my opinion the most useful abilty in the game. Five of the six Pokemon on my team (the sixth being Charizard) make use of the Sandstorm given by Tyranitar in various ways. From having the foe take damage, having a more powerrful attack, to being less likely to be hit, my team makes full use of Sand Stream. Tyranitar is the best Sand Stream user, seeing how it gets the Sp. Def boost, unlike Hippowdon.