Nikon Lens vs Tamron / Sigma

I have the Sigma 17-50 OS, and Nikkor 70-300VR and am very pleased with both. From what I have seen on these forums it's a coin toss in IQ between the Nikon and Tamron 70-300's. I got the Nikon used from B&H for 350, and would have grabbed the Tamron if there were no deals on the Nikon. I tend to use the 17-50 primarily for people photography so I can't speak to how it handles landscapes. I got the 17-50 to replace a stolen kit lens and 35 1.8G and wanted to see if I could live without the 35 1.8 (Which I really liked) for my type of photography, the Sig has not left me wanting.

Below are a few shots with both lenses. The barrel distortion in the 3rd shot is uncorrected so you can get a sense of the Sigma at 17mm.