Not too long ago I bought a MIO C310X, which is now discontinued. I bought it because I "knew" I could get European maps for it, which would handy for my trip to Europe in June. Well after looking around, reading whatever I could I came to realize here in the USA, not only could I not get the European maps, the USA maps were over two years old. Still I tried it out and then I also realized that the MIO takes some odd routes to destinations. Still it hackable and if one looks around there is a way of downloading and using not only the European maps but the most recent USA maps. It still takes somewhat odd routes but will get you to your destination. For $200 it is not a bad deal. Maybe a few are still available on eBay.
I believe that if the company that makes the MIO made available the maps, for a reasonable cost, there would be no hacking of the maps and they could have added some money to their bottom line along with some good Karma. As it is, I will probably never buy a another Mio, and money from my pocket will not go into Mio's even if they get around to providing the European / Updated USA Maps.
Want the maps, try googling - 2007.1 miomap - and follow your nose.
~Matthew