A hammer is about as personal a tool as you can get.
more so than a saw or drill. a hammer speaks to who you are and how you
work.

no one hammer is better than the other.

I like a light hammer, others prefer heavy weighted hammers.
I like a wood handle, others prefer composite or steel.

different styles for different uses.

personally I think the milled faces are for people who can't swing
straight... but that's just me.

You use a framing hammer for framing, a finish hammer for
finish work, and a tack hammer for light work.

The shape and materials of the head, claw, handle, and
grip affect things like moment arm, shock transmission,
weight distribution, grip, slipperyness, twisting,
and recoil.