I have a Trafficscope VRX and it has been faulty almost since I got it and I have sent it back several times. Tested it again yesterday in poor vis and it told me of a plane only half a mile away and 300 feet above. No idea which direction of course. A few seconds later a plane appeared and it was about 200 feet above and about half a mile away I reckon. I turned away from it but it was pretty scary.
The device didnt help me find the plane but it did make me aware to look extra hard at that point. Having said that I have seen plenty of planes nearby with no alert as they dont always have their transponder on.
I wouldnt pay £800 for it as I did last year as it has barely been in my plane and also back at Surecheck. It will be going back again this week as it keeps having a transponder conflict it says.
If you want to buy one I know of a cheap one