I am not a fan of CO2 carts. Yes, they are faster than pumping the tire by hand, but you have to execute perfectly, and they don't hold pressure. I think someone explained that CO2 leaks more readily from innertubes (smaller molecules than Oxygen?), but I figure that if the CO2 required to make your tire the size it's supposed to be under pressure is compressible enough to fit into that tiny cylinder, then it's not going to resist the pressure of your body weight as well as if you filled the tube with real air. In other words, why don't they fill those tiny cartridges with air instead of with CO2? Because it won't fit. But because CO2 is compressible enough to fit, then by that nature it will not hold your tire shape very well.

I still carry a full-size frame pump. Free air, and it keeps you warm on cold days.

L.