Geckos rock for Blasters. They won't turn haulers as well in the sand. You need at least some wheelspin. I loved my Geckos on my Blaster, they handled real well and they still had enough bite to do wheelies and make it up some gnarly hills.
i liked my geckos, they were pretty okay for traction and still gave you some good handling.. but if you take them out of the sand they will wear down quickly