I used Co2 for a while, but it had some shortfalls. I have Stan's sealant in my tires, and Co2 just freezes it into a hard little ball so it doesn't work. Also, if you don't get the patch right the first time it sucks to waste a canister to find that out. Or, what happens often, is I'll pick up a puncture and get a slow leak. Then, I'll hit a bump and pinch flat. So I'll fix one hole, and wind up flat again in 10 minutes which is a super pisser. I now use a good road-pump. A lezyne pressure drive. It gets the job done without killing the Stans; which in turn has kept me from flatting more to begin with. Sure, pumping up on the side of the road in 100 degree heat blows, but so does winding up going through both my cartridges when I'm 50 miles from home.