The first electrical shop I worked for used them exclusivley. There are many benifits. The tip holds the screw as though it were magnatized. It is nearly impossible to strip them. Once the tip is in the screw it doesn't come out until you want it to, unlike a slotted or phillips. And last but not least...not every trade on the job site has one, so if someone needs to move one of your boxes or pipes, they have to come get you instead of just hacking it apart! I am a big fan of these, and as Bob (Iwire) pointed out, alot of equipment is now putting in slotted/square screws on their terminlas, covers and dead fronts. I'll tell you the truth, I couldn't say enough about how much I like working with them.
