While this is pricey, I have no other bag that is as snug or as out of the way as this bag. With the Boa cinch, you can really get this thing snugged up against your saddle. If it doesnt, you didnt mount it to the saddle correctly.
In mine I carry an inner tube, nitrile gloves, a fixit sticks multitool, a Dynaplug tubeless tire patch kit, two CO2s , two Schwalbe tire levers, and a small tire inflator. I roll this up tightly and mount it and its very trim and compact.
When you need somehting out of this, you can lay it flat on the ground and roll it open. You tools stay clean and nothing falls out. You dont have to do the juggling routine you do with a small pack as you dig stuff out of it and then have to somehow hold on to it while youre looking for the thing you need. This is much more organized and much better, IMO.
Like most long time cyclists, I have a ton of these sorts of bags. This is the one that holds up the best, the longest and seems to work the best for me.
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.