Very very nice, the depth/lighting is amazing, the only thing which takes away from the sig is the text. But its a very difficult feat to make a sig with text that everyone will love, I stopped using it all together in my most recent sigs and just use the actual signature for my nickname somewhere in them, barely visible...so no complaints but I still "tag" it...works out for everyone.
Ya seriously, this thing is SICK! Text does let it down, as it does in most of your work, as it's the only thing that you haven't got perfect. I'd recommend taking the text off that angle. It shouldn't conflict with the flow as long as the placement is good. Also, any chance you could tell me where you got that render/stock?
I like it a lot, its really well done. I could ignore the text and just appreciate the background+render blending so nicely