As the buyer of a Samsung UHD "Smart" TV, I had the impression those guys knew what the word "SMART" was all about. But this assumption appears to be totally wrong. In the eyes of tv-makers smart means: it can connect to the internet. Mostly through a limited number of apps that are often: 1) user unfriendly (i.e. no support for a wireless keyboard) 2) not regularly updated 3) or not at all available if you have chosen a manufacturer (like Samsung...) that is not supporting developers to develop for their platform (=Tizen).
Sony is maybe one of the few that has picked the Android OS for their tv sets. So many apps are already available for these tv's.
I no longer wanted to wait for the Samsung boys to get their act together and bought a media player of the latest generation. For some $/€ 50-60 you can buy a very powerful box that streams all (well almost all..) content in the world to your living room. Kodi + add-ons installed on a fast processor on an Android box makes your TV set really smart. Also your old model!
Yes I use the Samsung smart TV App but it's limited. Do not see functionality to my music, only playlists. Finding it tedious to use having to manually type in each artist and songs to play. I hope they update it soon but at least the entire long songs play vs. others..where they stop after 10 min.
In order to keep improving, we're always testing new things on different platforms and with various user groups. We don't have any more info to share on 2015 Samsung TV models right now - but as soon as we do, we'll let you know!