Pulling wire? Going through studs/rafters/joists? You have
got to have good, new, sharp drill bits. These bits are specifically designed to bore quickly and cleanly through up to 3 layers of studs in one smooth motion...even with a cordless drill! Cut your install time drastically, use the right tool for the right job!
Are you thinking 'I have a drill set, what do I need another bit for?' So did I, until I found out, while in a 105 degree attic, that the bits from my drill set aren't long enough to make it into the stud cavity from above! Boy was I sorry I didn't have one of these bits that day!