For now, the update is only being rolled out to the SM-N910C variant of the Galaxy Note 4 in Poland, but it is just a matter of time before the Korean giant starts a wider roll out.
The Lollipop firmware for the Note 4 is based on Android 5.0.1 and brings with it a host of improvements and enhancements, including lockscreen notifications, Material Designed system apps, Smart Lock, Guest Mode and more. The update should theoretically also bring with it performance and stability improvements, but knowing Samsung, things can worsen as well.
If you live in Poland and have not yet received the update, don’t worry. It is just a matter of time before the OTA update notification pops up on your device. As for Note 4 owners in other regions of the world, it is likely that will have to wait for up to a month for the update to land on your device.