Nikon, but for only one reason... Redfield has been under 2 or 3 different owners in the last few years and they stopped honoring the original warranties from their old product lines.
If you're seeing no difference in quality, and the prices are close, the New Redfield Manufacturing just hasn't been out long enough to see if they are up to par vs old Redfield. Nikon has been a good, consistent go-to vendor during that same period.
Its not a BIG mark against them, just more of something I'd have to consider during my purchase. I have a very favorable opinion of old redfield equipment, especially their rings and mounts/accessories. hopefully the new guard is trying to make up for those past hiccups.
SC