Posted for "Matt Hapgood" <matt.hapgood@alumni.duke.edu>:

 Tom,
 
 Agreed about avoidance.  I do use WxWorx for tactical when VMC conditions.
 In those situations I can see the cells, but not necessarily what is behind
 them.  WxWorx gives me a good idea of what's behind them.  That way it keeps
 me from flying around a cell (VMC) only to find a wall of storms in front of
 me.
 
 If it's embedded in IMC conditions, that's when I give a very wide berth.
 
 Nothing is amiss with the GPS - when I use it on the road it's withing about
 20 feet (when I am at the intersection of X and Y, it shows me AT the
 intersection).
 
 The receiver is just getting coordinates and 1 & 0's to show digitized
 weather... so I can't imagine that it is the receiver.  I think it must be
 the software or information that is being sent to the receiver.
 
 Last week I made two flights.  On one flight there were many stationary
 cells.  They didn't move for over an hour.  WxWorx painted at least a few of
 them miles off from where they really were.
 
 Matt