I have propane because of the 'ease of use' factor. Get home from a long day at work and you're only a button click away from grilling. If it were a weekend and a party or something where the grills would be burning all day I'd prefer coal/wood.
Charcoal is the only way to fly. If you are in such a hury that Charcoal takes to long, you shouldn't be cooking outside to begin with. Charcoal all the way for me. I have 2 BBQ's and 3 smokers. Had a gas bbq once. Ended up ripping out the guts and linning it in tin foil and, filling it with charcoal.