The Mk4s are decent scopes but have several issues.
Leupold for whatever reason continues to instal milradian reticles with 1/4 moa turrets which never made sense to me. I look at it as having a foreign language reticle with english turrets. There is no way 1 milradian can be divided into 1/4 moa and come out with an even number.
Secondly warranty. The Canadian Leupold distributor will NOT handle any repair or warranty work on MK4s, and worse is the fact that if you do need repairs, YOU have to get the Cdn export permit and the apply for an IIC so Leupold USA can apply for an export permit in order to return your scope.
The advantages of NF scopes are that you can get them with moa reticles and moa turrets or if you have to go Milrad, they will instal at extra charge, 1/10 milrad turrets so the reticle and the turrets are both in the same increment of measurement.
I can not speak for all NF dealers but we keep open permits for Nightforce in BOTH directions, so if a scope I sell you fails or needs repairs you return it to me and it gets back and forth from the USA legally and with no bother to you.
The R1 reticle is in my opinion the best reticle available by any scope maker, the 1 moa divisions on the vetical line of the reticle make calling comeups, or use as accurate hold over very simple. The reticle is quite fine but easily visible.
The no added cost illuminated reticles are nice as well. The fact that unlike Leupold and S&B there are no wires inside the scope to illuminate the reticle, as NF has integrated their illuminated reticle into the side focus knob, is a huge bonus as the wiring and exposed rheostats used on secondary switching for illuminated reticles is the number 1 cause of scope failure in illuminated reticle scopes.
FFP is something you either love or despise, personally I find that having a reticle change size with magnification hard to use. The only real purpose for FFP is to be able to range at any magnification, I find my LRF is still 10 times more precise than any reticle will ever be.