Oh boi, armour, I love me some armour.
The second one is definitely superior. It has better shapes and the gold lining works really well, though I love the details on the gauntlets of the first one. I think something similar to the ones on the chest will make the design feel... umm, more designed? United? You know what I mean.
That being said, the chest plate in the second looks a tad too long, it should end around the elbow, so you got it right in the first one. But I really like the proportions of the cloth in the second one!
The greaves should follow the forms of the calf as close as possible, just sayin'.
The pauldrons are just weird, I get what you're going for, but... I think you can come up with something better. You've already got some very nice forms going with the (well, I don't know what it's called, the skirt-like part), try making something similar for the shoulders, it will make the design stronger once again.
I like that the left pauldron is different, that is an actual thing, but right now you've just added another layer, another opportunity for a wandering blade to get stuck inside. Not cool.
And the things on the back! We know capes and cloths and what not have no practical use and just get in the way, but I agree it looks cool. But maybe you can try giving it some colour, similar to the first one... just not that yellow-green. Maybe go for gold.
I hope you can get something out of my little critique, keep up the good work!
