Even if i come from the lowspec game dev side(wii&ds), i just can underline kevin johnstone's post. Of course you shouldn't waste polys on senseless edge loops and details, but it's the shaders and sfx, who send your performance to stop motion. To get our games on wii running 60fps our bootleneck is the shaders, which need to be simplified here an there. The vertex count is just a base issue and something comperable easy to optimize.