Originally Posted by
coupster
I only use the saddle rails for a bag. As seen from above, my load is a bit on the heavy side and I've never had good luck with saddle straps - could not get them tight enough not to move around and stay that way. I prefer the click on type attachment for the convenience and security factors, push button release, slide on clip and click to secure and off you go. As with all things saddle, to each their own. For me, its Fizik Arione (4) and KLICKfix bags(1).
For me straps work ONLY IF there are buckles of some type, velcro alone does not cut it. I have an old Cannondale tubular tire bag that has two zipper compartments; one on each side. It easily holds 2 tubes, a fold up 32mm clincher, patch kits, levers, chainlinks and a selction of allen keys. I use an old leather toe clip strap to attach it to the rails with no movement or shift. It has a velcro cinch strap and buckle for the seatpost. I have seen a newly made bag that is a near duplicate.