I actually had to return this seat roll. I wanted to love it because I think the design is very attractive and the materials are high quality. But no matter how hard I cinched it down on my saddle rails, it always managed to flip upside-down and dangle loosely. The diamond stitching, boa clasp, and all the other little details are very attractive but this bag needs another point of attachment (perhaps at the seat post) to stay snug and in position. Please don't waste your money on this bag. Let Silca redesign a better version first. For now, buy something else.
I always like a small compact saddle bag. This one is compact as well at techy with the boa system. The boa system keeps the saddle back nice and secure so that it does not move around. The price is a bit high but it seems like it will last longer then bags that use Velcro.