Samsung hasn't completely forgotten about its last experiment in curved screen design. The Note Edge on Sprint is getting an update today, and it brings the device up to Android 5.1. It was already running 5.0, so this is a nice surprise.
Sprint's changelog is not very helpful, listing just Android 5.1 and various bug fixes and enhancements. Presumably that will include all the usual Android 5.1 features like better heads-up notifications. The update (version N915PVPU4COFE) is just starting to roll out now, so it might be a few days before it's on all phones.