Could you please list your preference again, as in 1. 2. 3.... Not sure I understand the ranking.
Worst to best. Viper PST, then VX3/VX3i,then much brighter is the NF SHV, then barely brighter yet VX5/Z6. The glass quality coupled with the firedot reticle made the choice easy for VX5 over the swarovski. Accounting for price it was easier yet.
I want to state that this is not meant to be an all incompassing scope review/test response from me. It's anecdotal. It's my eyes, my preferences, and a very limited sample size of scopes. It's not intended to be a scientific evaluation of all scopes made, simply my observations with the scopes listed above.
I will state that I've hunted with my vx3 scopes for years and honestly held them in pretty high regard. My honest opinion is that I was utterly shocked by how much brighter and clear the vx5 was compared to them. The VX5 is closer to my BX4 Leupold 10x50 binoculars than it is to the vx3 scopes.
I'll explain my testing method. I have a certain deer stand in a cutover of 5 foot tall grass. The lane to the feeder is 180 yards and 50 yards behind that is full grown hardwood timber with the usual short bushes/timber at it's foot. One scope was mounted on a rifle, the other was sitting in my window shimmed up to point at the exact same spot. I could simply move my head from one scope to the other as light faded. I also payed close attention to set the magnification exactly the same. The vx3 is 14 power, the vx5 is 15 so I turned the vx5 down to perfectly match the magnification of the vx3. As light faded I noticed the line of underbrush at the foot of the forest. The vx3 lost the ability to distinguish this from the black of the forest 7.5 minutes before the vx5. Crosshair visibility was similar. This was performed on a bright sun shiny day with no cloud cover and little moon. So the point of that is that light faded rather fast. When I could no longer see through the vx3 at ALL, I could still have made out horns at my feeder, still see the wood feeder, still easily see crosshairs. It wasn't subtle.