It's much faster. If you're in a group ride and everyone is waiting for you - or they're not and you're hoping to have a prayer at catching back up - you want to change the flat fast.

Also, I'd like to know which pump you carry. Maybe it's my weak arms, but the only portable pump I've found that I get over 100 psi with is the road morph. My back-up pump is good for maybe 90 psi, and the pump before that was a little better but the o-ring blew out in only a year.