That sounds a LOT better! When you said the 320 core would be "1/4 the range of the 640", I just figured the 640 data in the chart X 0.25. I guess that was not correct extrapolation, huh?
Have you ever messed with a Raytheon W1000-9? That's another option I'm considering in the same price range. Both have features I like and dislike.
A 320 core has 1/4 the number of pixels in its array that a 640 core has, however what size lens also impacts the resolution significantly.