I just installed the app last week. It's a major file with the east region--over a gig to download, so you better have a high-speed connection.

Other than that, it went fine and is working. I think the part that is error prone is the updating of the new SD cards--which you won't have to do with your existing card (same as me). So far, my one complaint (and it could just be because I don't know how)--you can't delete more than one waypoint at a time. In other words, if you upload all your existing points, then subsequently rename them (which I do alot to organize them), deleting the existing points becomes a problem.

This is PLANNING tool. So far, I think it sucks at waypoint management, so you'll need a different tool for that.