Having read many of the comments, I thought it would be in the best
interest to share my experience. About 2 years ago I bought one of the
first versions of SureCheck's VRX alert systems, and have used it
often. About 6 months ago I requested a software upgrade, which they
did, and as well they asked me if I would be interested in beta testing
their newer XRX, simply because I also have the Garmin TIS in my Arrow.
The box I received represented overall the final product, minus a few
cosmetic flaws I'm sure.

My first reaction was that I was amazed that it is considerably smaller
than the VRX. It is odd looking, but easily fit on the top of my
instrument panel. They requested that I fly a minimum of 5 flights,
and record any, and all discrepancies, as well as any situations where
traffic was seen, but not shown on the display. The one question I
had was regarding the ability to accurately determine direction within
my cockpit, which is mainly aluminum. Their response was to that was
that they spent over 6 figures in development, and 4 patents to get it
right. Interesting...

Out of the 7 flights I flew with it, it accurately showed others around
me. There where times where the XRX would show traffic, and TIS would
show nothing even though I was looking at the traffic. At one point I
remember seeing on TIS a Cessna 421 300 feet below me about my 9:00
position and descending, where the XRX showed them 800 feet below me to
the right. The XRX was correct, and the TIS were off considerably.
The aircraft I was looking at was about my 2:00 position and on final
for LGB. I attributed this to the delay that TIS has. The majority of
the time the XRX and TIS agreed fairly accurately within maybe 200 feet
of altitude. The azimuth it showed was very accurate in my opinion.
One key thing that may be a factor is that you must set your aircraft
into it to help it determine direction. I did not notice any blind
spots, even though they said you may see some outage below you, and
behind you. I watched several aircraft past off my side and behind me,
however it tracked them with no problem in my perspective. Most of the
time when an aircraft first appeared on the screen, there was a 1-3
second delay before the azimuth was shown. In talking to them, they
explained that this was due to the sampling of signals.

My overall opinion was very positive. Minus a couple issues regarding
backlighting and power connection, which they said, would be corrected
for production, I think the azimuth it shows helps to really put things
in perspective.