Has anyone had any experience with the Tomtom GO 910 navigation system? I saw one this weekend and it looks like it has everything and more that Street Pilot has but doesn't cost as much. I also was told that map upgrades are free except for shipping the disk!!! This one covers the U.S., Canada, and Europe! The GO 510 is less expensive and covers the U.S. and canada. It, too, is supposed to have free upgrades.