leupold , hands down. Thought my new vx3 was a lot better than a friends monarch, he did too. it is still a very good scope though. With Nikon i wouldn't go down in the line though.
vortex , the diamondback anyhow 4-12 is not as clear in the woods as 15-20 year old vari-xii 3-9
and the 4-12 does not have any more magnification than a 3-9 vari-xii or the new leupold vx-2 or for that mater a bushnell 3500 3x9. low end power is close but upper magnification is not.
Sure looked good in the store though and was very clear in daylight.