I want to throw another vote in the mix for the March. I currently have two 2.5-25x52's and one 5-32, with a mix of mtr3 and mtr4 reticles. I recently sold the last Nightforce I had and I've had several! You can't beat the magnification range, weight and features of the March. The glass is as good as I have had my hands on.
I do like the Leupold VX6's for certain applications. I currently own a 2-12 and a 3-18. They are fine scopes for the money and I don't hesitate to take any into the field. However, on my rifles that are used for larger game and especially in areas where there is the potential of a trophy walking out, I want to be looking through a March.
Nightforce makes a great scope as well and I have no doubts that you could run over them with a cement truck and they'd be fine. If I didn't spend so much money on titanium actions, carbon fiber stocks and fluted barrels or drink alcohol, or if I ran 10 miles a day I might consider a nightforce again. I like lightweight guns with big brakes, really good alcohol, and not running four hours a day. Therefore I choose March.