Richard,
Wow! Being a computer guy I have to say this is impressive! Very nice work. I have to be honest though, I would not purchase something like this. When i fly I barely use my GPS. I like to just use the good old Mk1 Mod0 eyeball and a papaer chart. Even planning doesn't get real involved for me either. I am sure you have a market in the techno sector though. Plenty of folks who will pay for something like this. The update thing is going to be tough though. All depends on how much work/cost it is for you to do the updates then send out change dvds.
Nice though!
