I can most definitely say that the S&B has better glass than a NF, without a doubt. How much that is worth to you is a matter of personal preference. But, I've sat on the line looking through one and then the other, and the clear winner was the S&B. NF makes a good product, but they aren't the superior offering of the three you mentioned. However, you're going to pay a pretty penny for the superior offering. What do you get for the price? Superb glass, first focal plane, good reticle choices (I love the H2CMR), nice features (zero stops, second turn indicators, heavy clicks on whole mils, etc), and a scope that has a reputation for being "right" almost all of the time.
With that said, I don't know of too many dissatisfied NF customers, either.
I'm not personally familiar with the Razor, but I've heard good things about it so far. It's a new offering from an up-and-coming company, and I think you may eventually see prices climb on these scopes as Vortex gains more of a brand following within the industry. I seem to recall that the same thing happened with Nightforce back in the day, but I couldn't afford their scopes even at the lower price point back then. If that is the case, it might mean that the Razor is a pretty good deal right now. Regardless, Vortex probably has the best customer service reputation of the three companies you mentioned.
I'm running a S&B on my rifle right now, and I love the scope. It was a gift to me from my very generous girlfriend, and I don't know that I'd have spent the $3,400 on my own when considering that there are a lot of nice options out there for $1,000 less. But, it's a damn nice scope, and I've yet to find a scope that I like better... so, if I were to do it all over again and had to fund it myself (knowing what I know now), I still might have picked up the S&B. If you're willing to drop the coin on such an optic, I don't think the S&B would disappoint!