The latest software packs an abundance of new features including the Doze battery-saving feature and Google Now on Tap. Since this is version 6.0.1, you also get a fresh set of emoji characters and Android's recent security updates. Visually, the changes are mostly evolutionary as opposed to radical, but the general consensus is that Marshmallow and Samsung's tweaked TouchWiz bring a clean, refreshed aesthetic over the preceding Android Lollipop arrangement.
Having started out its life on KitKat before moving on to the aforementioned Lollipop, it's good to see that even at a time of one-year device life cycles, the very capable S5 is still getting the attention it deserves. Indeed, there are plenty of owners rocking much newer devices out there and still waiting, perhaps in vain, on Marshmallow's arrival. Thus, Sprint Galaxy S5 owners should count themselves somewhat fortunate that Android 6.0.1 is forthcoming.
The build number of the update being sent out is G900PVPU3CPCA, and is almost 900 MB in size. If you have been waiting for this one, it might take a little time to reach you since, as ever, it's a phased update.
As a side note, the Sprint Galaxy S5 Sport also appears to be getting in on the act, so if you own this rarest of beasts, head over to Settings app and check for the OTA.