only interested in pre planned ride directions.
I have not tried many units myself, but I think daytime visibility is the number one limiter. Motorcycle-specific units appear to have a stronger backlight that allows them to be seen better in strong sunlight, though not without some effort in full sun where I can't see phone screens or my car's Garmin nuvi 300. I can see my Tom Tom Rider 2013 edition ($350 or so at Amazon, including mount to a RAM 1" ball) in full sun as long as no direct reflections from things on the bike, like the plastic window on the tank bag, cast a direct reflection on the screen, so positioning is important.
I don't know if the $600+ units like BMW and Zumo are any better. I'd like to think so but, then again, they may be just overpriced. It would be interesting to hear if anyone has compared the cheapos with the expensive ones.
The Tom Tom Rider comes with a program called "Tyre for Travel" that allows you to define a route by waypoints. It operates as a shell on Google Maps and can import Garmin, Google Earth and BMW files, and export to Google Earth and other formats, which is great to do a fly-through to check the planned route. The program takes some getting used to but it works once you get some practice. It is developed and maintained by a guy in the Netherlands with frequent updates and bug fixes. It is definitely a one-man operation. Look for some you-tube videos.
I thought I had made a mistake when I bought it, but after a few trials and a first trip I am satisfied with it. Definitely does what you are asking for. My opinion is just a data point; Keep researching until you find what works for you and post back if you have any question about my setup. Safe riding.