I use the Beeline on my Street Scrambler. It's not hard to read, but it's not easy when streets are close together (read: was easier to use in Seattle than London. Also, easier to use on the motorway than in the city). How I tend to work it:
- Start up Google Maps and do my directions there (this is because beeline doesn't speak the directions)
- Start up beeline app and do the same destination with the same options (they use Google maps, so it matches)
- Ride off
For the most part, I'm using the spoken directions in my helmet from Google maps. But I can quickly glance down at the beeline and see how much farther I have to go till the next turn, how much farther for the whole route, etc....
Before I mixed it with Google Maps, I did get pretty good with just reading the directions. I started with Google maps because sometimes my next turn was 200mi away and I wanted to be able to ride a long time without glancing at the beeline to confirm my course. This way, I get an audible prompt when my course change is approaching.