I own a Vortex Viper 6.5-20 x 50mm Mil Dot. I absolutely love the scope. It's tough, accurate, and has excellent glass quality.
In my opinion, it is every bit as good as a Leupold VXIII, without the whopping price tag. I absolutely will own another one, and have shot some excellent groups with it. For the record, Remington 700 SPS Varmint, .308 Win.
VIGILIA PRETIUM LIBERTATIS
"The price of liberty is vigilance"
America is at an awkward stage. It's too late to work within the system, but too early to shoot the bastards.