There is a slight chance I might be able to get an almost new mk3 60mm unit for the same price as the Zues 640. Does anyone have any hands on with both units that could tell me if the Mk3 is worth it and why? The 10 year warranty on the Zues seem like a definite plus for the Aramasight models.

For most folks, the 4.5x native magnification is going to be a bit much for typical hunting. On the properties I hunt, I have feeders at 45, 85, 100, 110, and 120 yards. It is great at 45 yards if you are hunting mice, or if you want to shoot the left eye of coons. At 85 yards, it is tough to track moving animals. It has a very narrow field of view.

However, if you are a 100 - 300 yard hunter, I think it will be an excellent scope.

For general purposes, the Zeus 3 would be better in terms of magnification. However, you can get the MKII or MKIII in 2.5x and have a better general purpose scope than the 4.5x version.

I like both scopes, but they are very different.

What do you plan on hunting, how far, in what sort of environment most of the time?

Having both, I much prefer the IRD. Fall in love with the software again every time I turn it on.

Each has it strengths and weaknesses.