Punch when I'm on the move, regular guilotine cut otherwise.

I used to punch exclusively when I was starting out, but had a lot of trouble with tight draws, too little smoke, and harsh flavors if I moved my tongue while smoking.

After I got a CubanCrafters double blade guilotine cutter and used it a few times I started using guilotine cuts whenever I was sitting still. The draw is better, the majority of the flavor is better (can cause a little lip acidity/burn, though), and there was a better amount of smoke with each draw (so thus fewer draws, and a cooler burning smoke).

Really I think it's a matter of preference unless the shape of the cigar doesn't allow it. IMO the guilotine cut would be the best if you don't want to have a whole bunch of cutters lying around just in case you run into a pyramid or a chisel head or what not. It's a good multipurpose cut, if nothing else.