My TomTom Rider 2 got really confused twice while I was away in France, Spain and Andorra recently.
Firstly I had planned an itinerary from Pau to Caceres (using road junctions as way points, plotted really accurately). I was planning to go through the Valle de Hecho but the road was closed. So I used the neighbouring Valle de Roncal.
So I was 'off' the itiniary but still heading in the right direction. I thought that by the time I got onto the N330 towards Pamplona (part of the planned itinerary) that the device would catch up and map from there.
It didn't.
Secondly, and this did make me laugh, I had an itinerary planned from Lleida to Andorra. This time new road building scuppered the device ... so badly that when I arrived in Andorra la Vella for lunch (like you do) TomTom was (still) indicating that I should turn about and had 243km to go.
But it had its uses.
I used it to find petrol twice (once on foot after running out of fuel in Marbella leaving my chum's garage - actually I had a litre or so left, but the bike cut out down hill ... how crap is that?)
And I used it to find a hotel once (in Lleida).
It's great for finding your way in and out of urban areas. The road speed limit/speed display is useful (the km figures on the V-Strom's dial are a bit hard to read).
But it did plot an absolutely blinding cross-country route from the autoroute to St Chinian (SE France) sometimes through villages where the streets were only just wider than the laden bike, that I don't think I would have found using the maps that I had with me (1:800,000).
But ... maps and 210mm x 75mm paper strips (with decsion points marked ... a little teeny-weeny-bit like a Dakar road book) work best for me.
So ... is it a substitute for knowing where you are going? Definitely not!
Is it better than a map: No
Did I use it all the time: No
Would I leave without it: Definitely not.
Cheers
V61