I love the KG one because of KG!Needs moar blending and text needs word.Gradient maps are the ke my friend.
Your effects are over sharpened in this signature. The guy should be the focal, not the effects you used. Blur them a tad and work on the depth and getting the focal more defined. Silva Sniper, gradient maps aren't always the answer. I think the colors he chose for this tag are completely fine. I like the aqua color scheme, but I think you kind of over did it. His back is almost completely black and his front is way too bright.
The lighting needs to be work on. It is overpowering the signature a lot. Also, there is almost no flow at all in both signatures. There are random c4ds placed far from where the focal should be. Flow should go in some sort of line, running from one point in the signature in to the other, leading the eye instead of having it dart around everywhere.