The reason I have changed from a VX-III to the Bushnell 4200 is as follows. I have owned the Bushnell before and it's light gathering quality is superb and it takes a lot of recoil abuse and I love the rainguard. Been frustrated a few times down here in Mississippi over the last three years since our winters are so often wet and humidity is high that I have had to try and wipe a scope to see game clearly enough to take my shot.
Also, this 3-9x40mm 4200 has given me a better felt balance than did the VX-III did but that is a matter of preference and opinion on my part. The 4200 is good glass for the money and is actually a little brighter to my eyes than the VX-III is and I can see images earlier in the morning than with the VX-III. So, I sold one of my VX-III scopes and bought the 4200.