Anything new & improved re pump/CO2

I'm asking because I need to replace a little pump with a bracket that fit on my water bottle mounts. I am resigned to carrying a seat mounted bag with tube, tire levers etc, or tubular held with a toe strap, but that little pump was a Pita before it died. At home I have a traditional Silca floor pump, (including spare bits) so no worries there.
What do you prefer on the road? CO2? Traditional size frame pump, mini-type(are there good/better ones?) Is there sufficient nitrous oxide in a cartridge to fill a 25 x 700 tire? Is there anything left over?

Eric... pumpless, (but with spare and Schraeder adapter) in NJ.