4x with #1 clarifier for me.
With a 3x, you might could by without a clarifier. But its good you ordered the peep and clarifier just in case. Everybody seems to say that a 4x is all a person needs for 3D but I'm just a hair away from ordering a 5x to try.
I liked shooting with mine up until Saturday. Saturday I found out why people carry umbrellas when its sunny. We hit a section of the course where the sun was hittin in all the wrong places, and when I would come to full draw I couldn't even see the target through my lens. All I saw was a glare. I was actually looking around the lens to try and see the target. Needless to say...my score was horrible Saturday, and I'm sad to say that I may be joining the umbrella army.