Well armour is a difficult topic.
It should protect you better than the peasant stuff, but it should not have all the advantages.
Yes there are a wpf and speed penalty, but these are hardly noticable.
The tincans will now scream "lies!" and thats why i have made a video.
As distance i have chosen the double of lenght of the war spear with various load outs.
My athletic skill is 7 and i have needed
1.75 sec with the amazon setup (4.7 kg weight with 0 armour value)
1.77 sec with my standard light armour (9.4 kg weight with 24 armour value)
2.00 sec with a medium armour mailshirt (18.8 kg weight and 44 armour value)
2.16 sec with a heavy plate armour (37.7 kg weight and 64 armour value)
So in the end i gain 0.23 sec for for 50% of the weight and 54% of armour against medium infantry,
or 0.39 sec for 25% of the weight and 37% of the amour against knights.
running speedthe first part is normal speed, the second 50% slow-motion.