I tried Hammer/sjield a while back (mostly becasue i wnated to level up shield for speed boost) and was rather dissapointed too. Hammer dmage to power cost to cd seems a bit off. Maybe its becasue i didnt had right mods(i picked what i found nad crafted missing parts when needed), but hammer dmg for most part looked... well its not that bad, i woudl say good even, but considering downsides (hih PC, relativly high cd's, increased rage generation) it didnt seemed like good enough.
And shield was even more dissaponting. Too little surivability, only good things are armor restoration, and strong buffs for core/nice attacks dmg.