I am planning a trip next year down the CDR with my Zumo 450. I've been through several threads here, but there is a lot of conflicting info. I have BigDog's and Cannonshot's track files. I went through and built routes in Mapsource by tracing their tracks. Routes are in segments of less than 200 via points. They "preview" fine on the unit. I press "GO!" , pass on navigating to the beginning of the route, and use the touch screen to drag across and find the route - then zoom in - the route seems fine, and follows the Mapsource route (with just a few exceptions that I can work around.) I live 2000 miles away from the route BTW. Is this going to work in the field? There are some references to the route getting truncated once you are actually on it in other threads. Is that if you just have too many (more than 250) via points? I know you can just load the tracks and let the unit tranfer them into routes, but a lot of inconsistencies showed up when i tried that.