If you're going to cross back and forth with a single scope I'd suggest one with interchangable lenses. The 6-8x lenses are great for shooting spots but you run into a lot of focus and glare problems with them for 3D. I keep them down at 2-4x for 3D. I also prefer a flat lense to a convex/concave one for reducing glare issues. As with most things, the best thing to do is try a few out at the shop and see what you like. I really like my Specialty Super Scopes but there have been a lot of new scopes on the market since I got mine. You'll also want to play around with different reticles/pins.