If you pull out a mini pump on a group ride you deserve to be LFD.
I remember getting a flat on a group ride a while back... get the new tube and give it a few pumps with my mini pump to give it some shape before I put it in the tire. I could sense the anxiety in the rest of the group as they saw how pathetic my mini pump was; I'm sure they were trying to figure out how many thousands of strokes it would take.
Little did they know, it was one of those convertible pumps (probably why it's such a horrible pump), so after getting the tire mounted, I unscrew the handle, pop a CO2 cartridge in there and fill the tire in a couple of seconds while the group gasps, astounded at my mechanical skill. Or maybe the gasp was really a sigh of relief that they weren't going to have to sit around on a humid morning for ten minutes while I struggled with a dinky pump.
FWIW, I use the cheap 12g unthreaded cartridges and they are good enuf for me.