I can't say I have compared the NF to my Viper HS LR 4-16x44 directly, but as someone with an extremely limited budget (comes with having 4 dependents!) I can vouch that it is an exceptionally good optic for the money.
It's clear enough to let me ring a 12x12 steel plate at 855 yards with my Stevens 200 270 Win... Actually, let me be more honest and say its clear enough to watch mirage, make wind calls, dial accurately and then spot my misses as my cheap plastic stock allows terrible vertical stringing.
Financial restrictions aside, obviously the NF is a better scope all around, as is S&B, Victory HTs, etc. For me, saving for the $2k scopes is a multi-year effort that hasn't come to fruition yet due to many, many other priorities. Did I meantion I shoot a factory Stevens 200
The guys at Vortex are the only reason I get to really play at longer ranges at all. If you are in a situation like me, don't hesitate to grab one. I f you are wondering if the extra expense for top quality glass is worth it, well I'm sure the other replies have already answered that.