I'm told, by someone more knowledgable than me, that the RNS Tripmaster is a very good unit, which is used by quite a few competitors on the Dakar rally.
It's actually quite an expensive unit (here's a link)
http://rallyenavigationsolutions.com/product/tripmaster-xl² and I expect Honda were probably trying to give away a promotional item that fitted in with the theme of the bike.
It's nice to have a numbered item to go on the bike, although Honda UK seem to have completely screwed up a good idea by sending them out and not matching the numbered book with the numbered Tripmaster.
I for one will not get any benefit from it, as I rarely venture off-road, and to be honest there's probably not many places in the UK where you'll need to compare Tripmaster mileage with a roadbook or map; but, I like the fact that it's a numbered item and I have an early bike, so I will be fitting it, but not above the instruments where it has been configured to go.
Bob