when you update your software do you pick which one or does it get updated to whats being released now? I got my arc 4 from the first shipment that was sent out so it has none of the updates.
I'd always recommend getting the latest software. The last couple of changes had to do with handling the higher-powered cells better, fixed some minor issues when it comes to steping-down in brightness and more recently, set the find-me mode to Level-16 instead of Level-1.