Tough choice, I would lean toward the Burris mostly because of the ballistic plex reticle being available. However Nikon has a new reticle that rivals the ballistic plex out this year. Price/Quality points on both should be similar.
I don't know either scope but consider eye relief when scoping a magnum caliber. Longer eye relief for the recoil. Most quality scopes have this covered already.
Nothing like a cut eyebrow if you have to get too close to see well.
Others have offered up a sighting of roughly 2 inches high at 100 yards as a good sighting scheme. In my own experience I have come to favor a sighting of 3.5 inches high at 100 yards. This allows for the individual to hold dead-on (directly in the middle of the top and bottom) the animal out to roughly 350 yards.
Magnum calibers such as the 7mm Remington and 300 Winchester will extend this slightly. At 400 yards I hold directly on the backbone of the animal. The drop at this range allows the...