I have a custom 7RM that is my primary hunting rig and I've been using the NF NXS 3.5 x 15 for the last three years and its been a great setup!
I routinely shoot steel out to 1200yds and haven't found myself needing more, so for the ranges you mentioned it will be more than adequate. The low end is also really nice for hunting in the woods.
Ill admit I've been eyeing the new NX8 for the same reason, it gives me the low end for hunting and higher magnification for extended distance range trips. Having a 6GT built as we speak and Id like to transfer the NXS to the 6GT and put the NX8 on my 7RM.