Wait I am confused on the perk tree. If we want daedric we can't go around in full circle? How do ebony weapons compare to glass?
No, it is not a circle, think of it more as an oddly shaped triangle. You can go up light armor to Dragon, or Heavy Armor to Dragon, you cannot go around in a full circle.
General rule of thmub when it comes to "comparison". Heavy armor give you more protection but makes you heavier, light gives you less protection, but makes it easier to move around faster. When you spec far into the trees, both will loose their weight, at that point It really comes down to the final perks to dogde damage (light) or deflect damage (heavy). Just look at the all of the perks and make your assesment from there. Like weapons, one is not really "better" than the other, they work in different ways.