I have both, the 2.5 is great for the off hand quick to shoulder shots, the 4x not so much. With 20x you can shoot further then you really need to for hunting. Currently I have the 2.5x on my hunting rig and the 4x on my target range gun.
I have the exact same scope you are looking at in FFP, with the illumination its really easy to pick up the reticle at 2.5x, works great for holding wind at distance when you have to crank up the mag and not worry about being at max. Heck I killed a Mule deer last year at 57 yards with my NF and...
This might be a long shot but I am looking for a no limit ringer release. If somebody has one that they aren't using and looking to rehome it please PM me.