I have the MTX system on my CX commuter bike. No heel strike at all. It is the perfect system for my needs. Not cheap, but very sturdy and well made. I keep my tools and spares in the outside flap, and the rain cover in the inside flap. The lighting battery goes in the rear pocket. The trunk is big enough for light load days. The panniers hold a week's worth of clothes. When loaded the bike weighs over 40 pounds, but the load is rock solid stable.