Any of the 3 would be a good choice, heard good things about Big Sky but have no experience. You cant go wrong ever with a Bushness 4200, but I have always used a Burris, I love the optics, price, quality and customer service!! the 300wsm is what I used and I went with the Ziess 3.5-10X50, it is double the price of what you listed but it went on a custom gun and I wanted a scope to match, of the 3 you listed I would go with the Busnell, 2.5 will work in brush or out of a tree stand and the 10 power is plenty for long range. The bushnell next to my ziess is a very close second!