Where'd you see the Viper at?
Maybe Cabelas?
Definitely compare them on 4x. On some scopes it can make a big difference to eye relief and not so much on others.GTs. I didnt pay attention to the model numbers on the other ones. I should have checked that they were all on the minimum setting to compare them fairly.
In passing, Millet has been trying hard...but their crosshairs are formed from bent railroad ties and have an annoying tendency to come...off...under heavy recoil. Not that a .223 has heavy recoil, but their purpose-built long-range .50 scope looked kind of neat after most of the dots had relocated themselves to elsewhere in the field after ten rounds of 660 grain fun. So did the replacement scope's dots.
I've got a Millett DMS sitting nearby that was killed by 3 gun dump barrels. The ocular wiggles around now, so zero doesn't stay where you put it. I need to send it back and see if I can get it fixed on the cheap so I can sell it to someone I don't like.
It got the job done, but cheek weld had to be perfect at 4x, and there's tons of distortion going on.