Being a rather significant update, the Marshmallow download for the Galaxy S6 range weighs in at a hefty 1.2GB in size. So set aside some time to download this one and best not to let it eat up all of your data allowance.
Once installed, expect to find the well documented range of new Android features, including Doze, advanced app permissions, and Google Now on Tap contextual search. Samsung has a few tweaks of its own too, including a new web browser, TouchWiz user interface adjustments, and more convenient quick toggles.
The update does a rather good job at matching most of the features found in Samsung’s latest flagship handsets, so keep an eye out for that OTA notification in the coming days. Alternatively, you can find the button to force a manual update check under Settings > About device > Software update. Let us know when the update arrives for you.