I’ve snapped so many Robertson bits in my life. Screws are fine.

1 5/8" cement board screws

They used to be Robertson. They switched to Torx.

Night and day difference

Like you said, they do grip like a mofo, and with an impact driver, the bits snap.

I tried dozens of different brands of bits. Even paid top dollar for special Milwaukee ones.

I was at a point where I had to pre-drill and counter sink the screws because I was breaking too many bits.

I could probably drive a torx head one through a board