Aviation Consumer just published their thoughts on these portable
collision devices including the Monroy ATD-300, TrafficScope VRX, and
Proxalert R5. I thought I would share the results as I read them.
Their overall opinion rests with the Trafficscope for functionality,
and places the Proxalert at the bottom. I have flown with the Monroy
and Trafficscope, and can agree with them that having an altimeter
within the device seems to make a lot of difference. I have been
using the Trafficscope for a while now and can attest to its
abilities.

They made reference to the Garmin Mode-S system of traffic avoidance,
and claimed it is far superior. I would agree that any thing which
gives 3 dimensional views is a plus, however, they fail to mention any
price tags. I looked into installing the garmin 330 with a 430
display update and it would set me back about $17,500. For that price
it better give me really accurate info. One thing that does confuse
me is the service ability. From what I read they can give 3D info
within a certain volume by using the Mode "S" transponder. What I
realized is that if I travel outside this area I will be blind to
other traffic. This may be a correct assumption or possibly not, I
welcome feedback. For now however, my Trafficscope seems to do the
trick very well.