Locking system great, bottle capacity okay, bottle doesn't insulate so it's kind of expensive considering the only thing special about it is the molded bottle integrated with the connector. When I consider I've purchased two of these for both my bikes, it's almost $100! For that money, some sort of customized Koozie with cutouts for the bottle-holding mech would be nice to keep the ice colder for longer and sop up some of the bottle-sweat. Sucks when all that condensation goes right down to the Bottom Bracket on a hot summer day and your ice is gone in under 10 minutes. Another great idea would be for fidlock to make a bottle strap that works with the base so you can use other bottles, like those insulated ones. My only other gripe is that the nozzle is pretty bad. I usually just end up unscrewing the top to drink the water. I see they have newer bottles now with better caps, but not in the same capacities. That said, I still bought two of them and use them near-daily for about the last few months and have not had any issues with losing the bottle on jumps or aggressive trail rides.