Nikon 70-200 VR1 or SIGMA 50-150 OS?

So I have the chance of buying one of these TWO lenses for my D7100

1: Nikon 70-200mm f/2.8G VRI (Keep in note its the VR ONE.)

or

2: SIGMA 50-150mm f/2.8 OS

Priorities are:

Sharpness
AF speed / accuracy.

Which one is better?

I use the Nikkor 70-200 mm f/2.8 when shooting sports, horse shows and air shows. I rarely use the VR since when shooting such events is usually done using shutter speeds 1/500th second or faster.

AF-S lenses are the fastest auto-focus lenses when used on modern Nikon camera bodies

The Nikkor should last for decades. I have some that were built in 1970 and they still work perfectly on my Nikon D300 and D3

I have never used Sigma lenses, so can't comment.

Note: Just because lenses and cameras have a II version, does not mean that the first version was called I (one)

May be Nikon 70-200 VR1

The Sigma is a DX equivalent of the 70-200, but oddly enough it is as big and heavy as the Sigma 70-200.

Of course, the Nikon is going to be a better lens, but it is significantly more expensive. But the Sigma is still a great lens. If you are a professional and can afford the Nikon, then go for it. If not, and you are budget conscious, then the Sigma may bet th best.

I believe the only difference between the VR and VRII versions is the VR mechanism. I doubt the optics have changed.

The original VR version can be identified as there's just a VR ON and VR OFF switch, whereas VR II adds a Normal/Active switch. It is just a bit more refined and probably uses a different sampling rate depending on the switch position (normal/active).

You would use normal in most situations, and active when you are in a moving vehicle, train, etc.