So I'm getting close to finishing my new personal build and I'm having a hard time deciding on which Bolt & Carrier to chose. This will be a hard use training rifle and is made up of mostly BCM products.

Of these three which would you pick and why?

First: Umbrella Corporation Bolt Carrier Gen2
Second: The new Sharps Relia-Bolt & Carrier
Third: Old faithful, The BCM

Or if you have any other suggestions please suggest.