I also own a Razor HD spotting scope, 20-60x85 and enjoy it.
I spent like 3 months going in circles choosing between the Nikon HG, Vortex Razor HD, and the Melvin B2's. I spent some time behind all three and can tell you that you cannot go wrong with any of them. I like the way the Razors felt and they seemed to be all around good glass. However, I personally chose to keep the Maven B2's (9x45s) because I liked the way some colors popped compared to the other two.
I should note that I preferred the Razor HD 10x42's over the 10x50's.