I use it often and really like it. I even kinda agree with Hanaldo that often times it is not strictly necessary, but sometimes it is just a nice thing to give you a little extra piece of mind.

For complex shapes you have more wiggle room on the placement which can be very advantageous in case you have some race-tracking in some areas, or if you have a mold with small flanges only where you not necessarily have the space to place a resin break as big as you need.