For me, it wasn't a big deal because I always displayed my range on the instrument cluster using the signal stalk button. And even with the Dynavin installed, the display on the instrument cluster is still in "mls".

What I learned:
- the OBC is located somewhere else, not in the nav monitor as I originally thought it was (I was even driving around with the info turned off in the instrument cluster for a few weeks prior to the install to get myself use to not having it anymore...lol) The only thing you lose from the OBC is not having the ability to reset and/or make adjustments to some of the OBC features (e.g. timer features and the date/time from the OBC...the Dynavin has it's own internal date/time clock)
- besides, I figure if I do look at the OBC info on the Dynavin, it'll get me use to metric in preparation when the US will eventually switch to the metric system...lol