According to the tip Forums and forum posts, Samsung Galaxy S5 updated to Android 6.0.1 Marshmallow.
The update is about 900MB and will be able to download wirelessly directly from your phone.
Android 6.0 seems to have been rolled out to all Swedish customers, regardless of operator.
Given that the Galaxy S5 is over two years old, the phone will probably not get any big new Android version, so Marshmallow can be the final stop.
How do you already updated the new software works?