Doug Miller writes:

For anyone who does not already own a torch, and is trying to decide
between propane and MAPP, my advice is to go with MAPP. The MAPP torch
costs about $18 to $20 more, but IMO it's well worth it in the time
saved. The gas costs more per bottle, too, but I suspect that's probably
a wash in the long run, because you don't need to use nearly as much
MAPP to heat a fitting as you do propane; you may even come out ahead in
that respect with MAPP.

You may also be able to burn propane in the MAPP torch. I have a
Turner "swirl torch" that will burn either fuel; there's a regulator
adjustment you make when changing fuels. I find that it produces more
heat from propane than a regular propane torch, though not as much as
when burning MAPP. I tend to do copper pipe soldering using propane in
the swirl torch.

There was one time recently when I wished I'd switched to MAPP: I was
soldering a 1/2" side branch into a 3/4" tee. There was a brass valve
on the 1/2" pipe already, and the 3/4" tee had a brass valve on one
side and a pressure regulator on the other side, so plenty of mass to
suck heat away from the joint. And there was a slow drip of water into
the joint, which was continually being turned into steam. Despite all
this, the propane *did* get it hot enough to solder - it just took a
while.

Dave