I've seen various feedback on the TomTom RIDER 2nd Edition Motorcycle GPS system.
The on/off button is stiff but that also prevents it from turning on accidentally. Favorable as far as being able to use it with gloves on.
Written manual is not necessarily great but tutorials on the unit make up for that.
Doesn't have voice directions which some find the downfall of the unit but most rate it 3/5 for overall performance and ease of use.
As always Amazon also has a good variety of write-ups for the TomTom RIDER as well.