thing with armour is you want to avoid as much stickie outie bits as possible, because they allow a blade to stick/get tangled etc, where as with smoothness blades bounce off. so you cheat the blade of a method to pierce or tear the armour.
the ornate armours you tend to see in museums and the like are purposefully made that way to show of wealth while at tournament, so theres no real threat to life as it was, as your opponent isn't trying to dismember you just score points and thus lady clunge.
however being form fitting aslong as there no probtubants, ie: boobies, spikes etc. wouldn't actually have any major effect on how well it works, as long as you can wear a decent amount of padding underneath rather straight to flesh as it were you ll be fine. if you look at high medieval armour, 14-15Th cent you ll see the armour is actually rather form hugging, small waists, streamlined limbs etc. which all help in the deflecting of hits as its shaped rounded.
fantasy armours tend to be all ragh with bits sticking out all over the place because the 13 yr old designers have no idea about armourology and just do it make stuff look "good" i blame WoW for all bullshit fantasy armour that is in every mmorpg now, even my old favourite lotro, which i was part of group trying to get the armours look more realistic to which the designers told us most mmorpg players dont want realistic armour because their all retards so we wont do realistic armour so people keep playing, haha jokes on them with their dying game. but i digress.
armour smooth good
armour knobbly spiky stickie outie bad
ps: clunge isn't recognised by spell check!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!