First of all, VA is one big speed trap. I drive in Maryland just as much as Virginia, but Virginia has about 2 times the amount of speed traps Maryland has. LOTS of constant on radar in VA. Cops like to hide from eye site on the side of the road or the median and run constant on radar. Moving constant on radar is also a trend here. A lot of times they just drive around with moving constant on radar and make u-turns and nab somebody. Cops here seem to like to hide behind bushes and overpasses with constant on radar. Another popular set up is constant on radar just on the other side of a hill.
I have only seen instant on set up twice. One time was the state police on interstate 95 a little south of Richmond using Ka band. He was parked on the right side of the road partially hidden in a brown unmarked Impala using his side mirror and his rear antenna. The only other time I've seen instant on radar was on Route 17 in Faquier County. This time it was a marked state police car sampling the oncoming traffic with Ka band as he drove. My X50 gave me plenty of warning in both cases.
You will find slight laser use in densely populated areas (Northern VA, Norfolk/VA Beach area for example).
If you are passing through VA, I suggest you ignore the brown sign with white letters that reads "Radar Detectors Illegal" and leave your detector up if you plan on speeding. Just take it down when you get near a radar source or see a cop. If it's night time on the highway, it's likely the cops won't see it at all in full dark mode. As you can see in my post in the Spectre/VG2 section, the penalty if you get caught with a detector is weak.
Although not as common as radar, nighttime pacing is used in marked and non-marked (seen Ford Explorers, Dodge Stratus, Camaros, RAM 1500 truck) police vechicles. So never let your gaurd down if you are using a detector. Hell, I think that is good advice in any part of the USA day or night.
BTW, the biggest speed trap town (my opinion) in VA is Vienna. About 50 cops that do traffic for a tiny town in Northern VA, they will stop you for the most minor offenses (5mph over for example) and they never give warnings.
Roy, your site is great.