I've been using Routis so I have a couple of suggestions that I think Routis lacks. Overall I think Routis is a very touchscreen friendly application, it's more features I'm thinking of.
1. Routis has a box that displays your toute to a destination. It allows you to highlight each road. It would be great to be able to highlight the road and toggle it for avoidance. It gets dropped into a new window listing avoids. You can then on the fly move it from avoids and have it reroute. This is for when there's a traffic jam or accident and you want to hop off the highway to get around it then get back on the highway. So, this is partially interface and partially a new functionality.
2. It would be nice to have speed displayed somewhere in the top or bottom bar that show your current street and your next street to turn at (rather than have to have the whole GPS data info box pulled up). There's plenty of room for some data in these bars.
3. Around the edge of the map, there is an arrow showing north (if it's set to rotate). I'd also like one to show the bearing of my final destination in case I'm ignoring the route suggestions and just want to try to head toward my goal (maybe it already does this, but I don't see it).
Ok, so I guess most of this is functionality but they all have GUI components

. I've only used Routis and Mappoint so I don't have anything else to compare it to, but I really like the Routis interface and the way it minimizes the menus to use the full screen for a map.