I haven't had the chance to look through a Viper, but I did purchase the 11-33x50 Razor last week. I tend to prefer better glass vs extra objective size and increased magnification, but others may have a different opinion. I purchased the scope for range use out to 400 yards, and to have a lightweight compact scope to take out west to view game up to about 1-2 miles. So far, I haven't been able to test this scope beyond 500 yards, but I have been impressed with its performance. Yesterday evening I was reading the license expiration tag on a vehicle parked about 390 yards from my house. I then ranged a house at 478 yards and was able to make out the texture in the brick. I believe under the right atmospheric conditions (limited heat waves) I'll be able to see 30 cal bullet holes at 400 yards, but we will see. For the price I have been happy with my purchase so far. Now that I have the 50 mm, if I got another spotter I would skip the 65 and get an 80-88 mm.