Should Mountain Bikers Use Saddle Bags

When hitting the trail it's handy to have a cycling light saddle bag with your essentials. But no one wants a rattling saddle bag. If it's not rattling, then how the heck did you pack it so tightly and furthermore can you open it without busting the zipper. The truth is, mountain bikers need to carry more gear, be it tools or spares. Perhaps a hydration backpack is more appropriate.