Hey Action, nice materials... I find the settup a little bit CGish (if you know what I mean).
I cant nail down exactly, but I think it might be related to:
*Sharp shadows: most product renders are done with very big area lights that result in smooth shadowing (http://www.coolstylefashion.net/wp-content/uploads/2011/10/Photography-Studio-1.jpg
*Completaly blacked out areas: The right part of the image (including the forground object) have areas that are completally blacked out. In a studio setup photographers would be carefull to have information in all portions of the image, you can have contrast, just not that much contrast.
*Overly saturated materials: specially the ground is very saturated. It might also be related to the diffuse value being too high, as most diffuse materials in real life tend to reflect only up to 70% of the incoming light. (with exeption of some weird materials like the spectralon).
There is also this tool called lightsmith which comes with a bunch of HDRIs wich you can use to produce studio like ilumination and reflections. It will automagically place the lights in SI with some pretty useful gizmos. It will also setup light emission in a optimized way.:http://hdrinews.blogspot.com.br/2011/03/lightsmith-lets-you-craft-your-own.html
Ps: For great product renders always work on a Linear Workflow and have GI turned on