As noted, you will find them (wedge punch shots) invaluable as a yardage gap filler between clubs.
Also as noted, they have a lower trajectory and more roll than a full shot, so I wouldn't recommend the punch when approaching an elevated green with the pin cut close to the front. (Think BPB #2 or #15 in this context.)
The wedge punch is also great on the green for getting over long stretches with tough breaks. You'll need to experiment for distances, as you'll only get ~half the yardage compared to the same shot off fairway or fringe.