I am considering the BR double strap as I shoot sports with a 1dmkIII and a 1dmkIV. On paper this strap appears to be just what I am looking for but as it is quite pricey, I would be very interested to hear from anyone else who may have practical experience of using this.I have been paying close attention to the pro-shooters at F1, Football World cup and other top sporting events and have not noticed the