I use Streets and Trips also. One thing I really hate about it is if a road is say I94, US6, US49 most people not from the area know it as I94 only. Streets and Trips will label and refer to it sometimes as US6 or US49, not I94 so I think I will have to get off the Interstate for some reason.

I also use Garmin's Streetpilot III so the Streets and Trips is just sort of a backup anyway.