I assume this device is reading the rpm and road speed info at the ECM and calculating the gear position, similar to the sixth gear light on the current models. So it could be subject to some of the same problems the stock sixth gear lights have had, and if you change gearing all bets would be off as well. Might want to research the reprogramability of the unit if you're thinking about a future gearing change.
Maybe I'm just "different", like people have been saying most of my life, but I figure if that little box can look at rpm and road speed and figure out what gear I'm in, and my bike has a tach and a speedo, I can calculate that stuff myself on the fly without adding another display. And that's pretty much the way I've done it for the past 35+ years.
I did actually have a Honda in the 80's that had a gear indicator display, and after the novelty wore off I pretty much ignored it except for verifying neutral.
Jerry