I can't speak to which has a 'better' weather display, but I went with
NavAirWX, and have flown with it for well over a year now. I can't
imagine flying without it.

I had a rather negative encounter with the Control Vision folks at OSH
one year when I was doing my research. At the time, AnywhereWx was
still using the sat phone for weather data, but NavAir had already
built prototype WxWorx XM solutions. So NavAir was at least 6 months
ahead of Anywhere on the XM technology side.

What burned by hide on Control Vision was they 'neglected' to inform me
during my discussions that their sat phone solutions had compatibility
problems with the KT-76A transponder. I later found out that most older
KT-76As would interfere with sat phone reception, and prevent weather
data from being recieved. But you still pay for the sat phone minutes.
Sounded fishy to me, and a few individuals reported problems trying to
get refunds from Control Vision when they found out the system was
incompatible with their avionics. Control Vision's solution was to tell
the owner to go out and replace their KT-76A... I wasn't in the mood
for that kind of crap.

Seems to me Air Gator did their homework, and had XM technology a good
6 months ahead of Control Vision. The guys at Air Gator have provided
outstanding customer service. I had flow from VA to FL, and my XM box
decided to deactivate. Air Gator called me back on a Sunday night to
help me re-activate my box. I had a power cable go bad, and they
replaced it at no cost. They are always providing updates and
improvements on their product. I now fly more days that would have left
me on the ground were it not for having great situational awareness and
strategic planning tools 'on the fly' so to speak!

As far as the weather display, All I can say is outstanding. Having
lightning strike overlay on NEXRAD images in near-realtime (I average
5-minute updates) is incredible. The airports are also color-coded so I
can see who is still IMC and VMC from a ways out.