Considering the final block perk uses sprinting, light armor has an advantage there with no need to waste perks in such junk as heavy does to match it.
Then considering both light and heavy can hit the armor cap anyway(can hit it w/out exploits even with just elven if you get 100 smithing+vendor/found potion), advantage to light again. And light's 10% dodge is > 10% reflect easily.
Heavy of course has an armor advantage early on, but not enough to make a huge difference. The main advantage heavy has is that the best weapons are daedric(heavy side of smithing tree), another early game advantage for melee in particular.
I won't argue over which tree is better--I have different preferences depending on my build--it just seems odd to me, since shields are for soaking damage and opening up for counter attacks (the latter of which I suppose would help a light build), and it so very well compliments heavy armor's focus on tanking and stagger absorption. Also, 10% reflect > 10% dodge: that's a 10% chance to reflect
all damage from a single strike, and, as I understand it, not take damage from that strike--essentially a dodge/counterattack. If I'm wrong, however, and the PC retains all the damage of a reflect while also reflecting it, then perhaps YMMV; whether dodging an attack outright is worth more than taking the hit and giving it back depends on the player.
Anyway, I find this very interesting. Such a build sounds nice at higher levels, but what about getting there? You're still soaking up damage with an armor type that's not built for durability (and I realize all armors can reach the cap, but I was/am not considering that).