If you still can't decide here's an advice- maces are good only against armored foes such as NPCs because it neglects certain % of armor. They aren't good againts, say, dragons, cause dargons have no armor to be avoided thus using axes is better because axes cause bleeding, and on master axes can make dragons lose like 2/10 of HP from bleeding alone. Swords and axes are also faster than maces. And finally swords are somewhat between both- useful against both having the effect of doing random critical damage which can be better than both if you have luck of doing often critical strikes.
Maces are good against any creature, they have higher base damage and higher stagger chance. Especially the Mace of Molag Bal. That thing is just
wicked. There's also no good 1H Axe Artifacts.
Volendrung is a Warhammer that hits harder than Greatswords, but swings at the same speed, if not faster, and staggers the crap out of everything. It also absorbs 50 Stamina each hit, allowing you to spam Power Attacks as you drain your opponent. It's a clear winner.
450-500 hours of playing, probably hundreds of kill animation, and i've never beheaded anyone with a mace.
I decapitate people all the time with the Mace of Molag Bal. It's kind of funny, seeing my char spin and swing his mace into the enemy's neck, just to see their head get
sliced off at the neck. You'd think it'd
tear his head off, or cause it to shatter and explode, rather than slice it off.