Well, I broke down and bought one of these systems recently and finally got to try it out this evening on a cruise around town. Seemed to work pretty well, though I did have a couple of false readings. One was when a car turned out from a side road just after I passed him. The sensor did not pick him up. Not a real problem in that case, as I saw the car waiting to pull out.
Seems to work best with a car approaching directly from behind. Claims to begin sensing at about 150 yards. I would say that was pretty close. I did a couple of dry runs waiting on the sidewalk for cars to approach. No problem registering cars and trucks. I did not get passed by any motorcycles, so that will have to be determined later. No bicycles from behind either, but I'm not sure it will register those, unless it was the whole peloton!
Batteries are supposed to last for five hours. I was only out for 45 minutes, so no problem there. Mounting the units was not difficult. I did not use the seat post mount, instead I used one of the extra supplied bar mounts to affix to the saddle bag. If you use a bag and your saddle height is significant, you won't need to do that. They actually give you enough mounts to do two bikes if you set them up properly. Then you can just swap the receiver and display units from one bike to another.
One additional thing.......it is still a good idea to have a mirror of some kind unless you are adept at peeking behind you.
Tad
