Before I say anything, I must say that I am biased against these types of renders because I got sick of them a few years ago and the disgust is still there. That said... I'll try my best to be fair.

Anyways, looking at both of these, the bubble looking things don't really fit in with the renders and I think that when used in a sig, as these are sure to be, that would have to be cloned/healed out of there.

The wire frames... I think you went a little overboard of them.

I like the material used. I like the reflection of the light source on the first one but there appears to be two light sources going which doesn't work out very well, imo. The second one is much better in this respect.

There seems to be a little bit of a blue tint in some areas that doesn't seem to fit in with the rest of the image.

I apologize for the lack of positive comments. >.<