Well, I use them quite a bit (pardon the pun!), as we do LV wiring (audio/video, comp. ntwkg., etc.) as well as power wiring.
It is of utmost importance to know where the tip of the bit is at all times.
The aiming handle is a good accessory. They do require a few screw-ups before you get good with them.
Don't ask about MY learning curve!