I've got some cuts to make for the gabled ends of a pole barn. Says
you can use a steel cutting blade on a circular saw, a regular blade on
backwards or you can use a nibbler or shears.

Anyone have any recommendations? I'm more interested in speed than a
super clean cut. (The flashing will cover it anyhow.)

Thanks much.

You might try a metal blade in a Milwaukee Sawzall. however
be sure you shake/rinse off the rest of the sheet well after you put it
up as the filings will wreak havoc with the finish of most painted
metal. If you use a set of three jaws or nibblers it will be slower and
they tend to scar the sheet an inch or so out from either side of the
cut and the ribs are a bit tough. The cleanest is to cut by hand with a
set of offset shears but the fastest is the saw option.