I'm looking at the Armasight Zeus 2x16 640, and the Armasight Zeus 3x12 336. Only reason I'm comparing the 2 is the 640 is on sale for 10% off. I've found out the only difference is it also has a double quick disconnect mount, instead of a single on the 336. Then I got to reading the specs on the detection and recognition. Now this is what blows me away. The 640 is 900/600, the 336 is 650/400 IIRC. I'm wondering what magnification they are doing the detecting and recognition on? Is it the 16X vs the 12X or the 640VS the 336?