I have the smaller version of this seat pack and love it. But I also like to carry an emergency tube even though I'm running tubeless now. The smaller version is just a little too small to accommodate tools, inflator, CO2 canisters, AND a spare tube. This size can handle it all.
This is my new favorite for size, utility and appearance. Perhaps a little less style than the Capsule, this has a bit more room and looks and feels great
The size is great, big yet compact. But the Mattone lacks the red pull tab that makes it more difficult to remove from the bike seat than the Premio which works like a charm.