They're two different types of weapons. Krom doesn't really do crowd control, but the himmin afl is not going to be nearly as effective in 1 on 1 (at least for strong enemies).

I prefer mistwalker and shield for most combat, and himmin afl for crowd control / AOE. I haven't found a reason to make krom. I think mistwalker is slightly more effective in mistlands due to the elemental damage, and krom is overkill for the lower biomes.

I tried a run using polearms as my primary weapon, and it's the only one that I gave up half way through. I just didn't like using polearms as my primary weapon and couldn't see it getting any better. (YMMV)