Kind of a S7 vs. M4 debate here, which ones better? Do you guys prefer the 8500 with its S7 platform or the 8500 X50 with its m4 platform? I hear that the S7 is generally better at off axis detection, is this true? Is the pop mode that useful in the X50? If it makes any difference I drive in South Florida, Ft. Lauderdale area, mostly city driving.