I had a couple issues small with the VIVA bag loops that are worth mentioning. The clamps would not tighten down on the rails or my vintage Brooks Pro. VO mentions that issue on their website and I used some cloth bar tape on the rails. The loops seem to slip periodically, despite my best efforts to tighten the hell out of them.

There is an upside to those loops. Since the loop is made of thin steel I can clip and loop just about anything with them, plus you can adjust the height if needed. I cannot do the same with my Brooks B72 with integrated loops. I have clips that I use as a DIY quick release and they won't fit on the B72.