(For 1/2" 3/4" etc)

I see two types:
One type fits around the pipe and uses two screws fastened into the
wood (or whatever)

The other has a round copper piece where a large wood screw goes
through the middle and then two pieces with two copper screws hold the
pipe in place.

The first type seems much easier and cheaper but there must be a
reason or specific application for the second type. Anyone know where
to use the second type?