Which bits? The two most popular are the turbomax bits and the cobalts. I personally have the turbomax bits and absolutely love them, i've drilled tractor trailer frames with them and never had a problem. They have the double cutting head, they're self centering and anything larger than 1/4" is warrantied if it bends breaks chips or dulls.
Just pick up that set its awesome best drill bits I ever used . Driver said he will warrenty the front 2 rows if any brake or need sharpen . Just the last row he won't the smaller size ones. Like the durable steel case they come in . Seems like everything is in plastic cases now. He also told me they are Irwin drill bits In Matco case . Said Matco owns Irwin.