Posted for "Carl Cadwell" <CarlC@Cadwell.com>:

 Colyn,
 
 I fly the XM WxWorx on a Toshiba Pentablet all hardwired (no Bluetooth
 wireless) in my Lancair IVP (about 500 hours with Wx on board) and WSI
 in the Epic on the Chelton system (160 hours).  I don't think I can
 comment on the quality and accuracy question you are asking.  I can
 relate my experiences flying with both of them.
 
 
 
 I like them both.  I won't fly IFR without them anymore.  They can help
 keep one out of harms way.  They are both seem equal in knowing where
 you can fly safely and where you should avoid. They are both very useful
 to knowing where you can fly (deviate) to stay clear of weather systems
 or buildups.  Overall the flights are much smoother as one deviates to
 avoid weather.  I would never use either for penetrating a line of
 thunderstorms, nor have I attempted to do such.  They both help avoid
 icing if you stay out of the green.  My wife loves to be the onboard
 weather maven keeping me up to date on the metars, cell movements,
 distant areas of significant weather we are flying towards and what is
 happening elsewhere around the country in the weather department.
 
 
 
 WSI is more convenient in the Chelton as it is displayed on the moving
 maps, comes on automatically and is dash mounted.   It is more reliable
 in having the data available.  It has only failed to provide data on one
 occasion.
 
 
 
 The XM WxWorx on multiple occasions could not be used as I could not
 connect and had to call and have the program reactivated several times
 (4 or 5 times), the receiver antenna failed twice and the GPS 3 times.
 In every case XM and WxWorx were very responsive.
 
 
 
 Carl Cadwell