It always 'depends' but I always wear a helmet and aero helmets ARE faster than normal road helmets so there's that one answered. Shaved legs might be faster and they look better so there's that one answered. Overshoes might be better - they might not, the difference isn't going to be much. I wear them although I couldn't adjust my shoes yesterday so my foot went numb which has more of a negative effect than the positive aero benefits I may have received. I believe skinsuit materials have tested faster than skin and they offer some compression so probably faster. You also don't break any indecent exposure laws.
It always 'depends' but I always wear a helmet and aero helmets ARE faster than normal road helmets so there's that one answered. Shaved legs might be faster and they look better so there's that one answered. Overshoes might be better - they might not, the difference isn't going to be much. I wear them although I couldn't adjust my shoes yesterday so my foot went numb which has more of a negative effect than the positive aero benefits I may have received. I believe skinsuit materials have tested faster than skin and they offer some compression so probably faster. You also don't break any indecent exposure laws.