I've used one for two flights. Did not like it. Had to reboot the darn thing at least three times during a two hour flight. I don't think Windows is a good platform for a GPS, or anything critical for that matter.
Cheers, Pete
 
I have had one for about a year and have used it for many flights, I have not had any problems with needing to reboot. The functions are easy to use with the aviation mount not to easy in flight without ( using the stylis). With the pda and mp3 player and terrain avoidance it has been nice.