I've got the CED M2 with Infrared Screens (these are essential, it will work consistently in any lighting conditions, with the screens)
It works really well & I have confidence in it.
Also included is software (windows only) & USB cable so you can download results to computer.
Another useful function is it will speak the velocities as they appear on the screen.
The distance between the two sensors is 2 feet, which is one of the reasons I believe it is very accurate.
The only downside is it is not very portable like the SKAN