I ride most of the time with a pump. Have for years but I did get a co2 inflator to top off the tire. The first one I had didn't have the control valve so when you screwed the cartridge on it was punchered and used up all the co2. Not very efficient. The second was this Silca one I got sometime in the late 80's or early 90's don't remember when.
I went on a ride with friends once with no pump just three cartridges, thought that would be enough. One of the other riders flatted three times and didn't have a pump so I let him use my inflator and cartridges. He bailed on the end of the ride, an unsupported century, and I flatted about twenty miles later. At this point I had been dropped by the other riders and no-one was answering my phone calls so I walked about two miles before they figured out something was wrong and came back for me.
Needless to say, I don't ride with out a pump anymore. Still carry the co2 but always carry a pump.