What is the problem with pentalobes?

Pentalobe & Allen (Hex) head screws face the same problem when the screw is a soft metal (stainless steel). The heads side wall can flex if you over stress it which then makes it harder to remove as it jams.

Phillips (cross point) screws depend on more of a downward pressure so you do need to be careful you don't apply to much downward pressure.

The lobe points can sheer on either as the Pentalobe & Allen have less meat so they tend to go before the phillips.

Straight slot screw's tend to sheer at the base of the slot as the heads wall tangs tend to be weak. Which is why many people don't like them.

The only winning point for Allen, Pentalobe or Phillips is if you need to drill out the screw the hole is centered so the drill won't skate.

I think the real issue for any tight screw:

• Use the correct bit and make sure the bit is not worn.
• Don't over stress the screw, consider a screw thread lock might have been used so you need to soften it before attempting to remove.

As to why companies use Pentalobe screws over Allen is mostly an issue of size. One less lobe makes a better screw when you get small.

In either case the self feeding drivers used in the manufacturing floor handle the Pentalobe or Allen screw better than the Phillip screws. As Pentalobe is a newer design its still under patent control, whereas Phillips is no longer covered. So Phillip screws are more ready available & cheaper.