So I went in the Mississippi Gate at Buckley AFB on my way to work yesterday. As SOON as I turned into the gate area, I got a K-band alert up to 2-bars. I had to unplug the RD going through the gate (can't use 'em on base), but as soon as I got through, I saw a YOUR SPEED sign ahead of me. So I plugged the Pro 73 back in and after it cycled, I confirmed it -- the sign was the K-band source. It was only 4 on the meter when I passed it, but it had just finished cycling on.
So .4nm on a weak Your Speed sign is pretty damn good for a "NON-TOP-3" detector. I was pleased! Probably would have been farther had I been straight-on and not pependicular to the signal at first.