I tossed my K-band MPH K-55 in the car when I left for work this morning. During my lunch break I did some testing with it.
At work we have a parking lot that is parallel with the street (a long road with a 30 mph limit, and traffic speeds averaging 40 mph of course). I parked in a parking spot closest to the road (maybe 3 or 4 feet of grass between the lot and the road) so I could get some more accurate speed measurements.
Here's some notable observations I made while "playing":
1. If I had the car on, I had to turn off the A/C fan or else the radar would "clock" the fan instead of traffic. I didn't bring the mounting bracket with me, so I had the antenna sitting on the dash. Moving it around didn't help.
2. Most traffic was moving at a speed closer to 40 than the PSL of 30.
3. The radar could clock traffic as far as I could see it (1500-2000 feet, a wild-a$$ed guess).
4. It would clock traffic coming and going, and (as expected) it would tend to lock onto larger targets, or the closest target. One time a tractor trailer was approaching, and the radar locked onto that and "ignored" traffic going the other way until the truck passed.
5. When I used instant-on, I could get a reading within 1/4-1/2 second depending on how close the car was. The V1 responded to the K band at about the same speed. Moral (as we all know): if you're the lead car and you're instant-onned, you're dead, no matter what RD you use. With a quick finger, I could quick trigger and get a reading within 1/2 second, but the V1 detected the burst pretty reliably (in one case, it didn't, but the K-55 didn't get a speed reading either).
6. I took a short drive with the K-55 in moving mode and it worked well. It also confirmed my speedometer is accurate, at least up to 45 mph or so, which is the fastest I went.
Later on this week, I'll repeat this experiment with my Ka-band Stalker ATR.