Co2's are great! Maybe have a mini-pump on hand to get the tube slightly inflated or I just use my mouth and once I know it's seated properly and ready to pump up I use the Co2. I have a combo Co2 inflator/pump that's so cool my hubby stole it but its drawback is that it takes the larger threaded cartridges, which are more expensive. My simple one takes the cheaper, smaller non-threaded version. It's the one thing I buy at walmart (in the gun section), I still have 3 of the dozen I bought 5 years ago.
A drawback to Co2's is their tendency to freeze the valve shut when it's cold. So far it's been dealable.
I also run Tuffy liners between tube and tire to prevent flats. They make lighter weight versions of these too. The only problem with the Tuffy liner that I've had thus far is that the end of it wears into a tube and can cause a flat. This has only happened to me once and it took 6 years to do it. For 6 years without flats I can live with the inconvienence. Come to think of it, most all my Co2's went to friend's and the hubby's bike-til he took my liners out. He doesn't like them, I guess because of the weight thing. I've got to get around to putting them back in...I hate fixing flats!!
I used to have an open mind but my brains kept falling out.