What device has the best Plex app at the moment best looking and most features etc ?
There are two camps the Plex Media Player
group and the OpenPHT (or RASPLEX)
group
Plex Media Player, shares the same UI as all of the updated plex built apps.
OpenPHT and RASPLEX continue to use the interface from the previous UI of Plex Home Theater.
Currently OpenPHT and Rasplex have the most available features and customizable skins to use with it. But if you like the new UI that plex has been using then you may want to look at Plex Media Player.
“Best” is relative. (We will keep my relatives out of this) Also it is subjective. There is a version of Plex Home Theater that many will swear is best when running on a dedicated PC. Others will say that as long as performance is adequate the ease of operation is paramount and clients like a Roku are best when running the latest release. The Raspberry PI and other systems running Plex Media Player are preferred by other folks.
For me I am of the belief that a Roku is the “best” but it is far from perfect and is still undergoing updates and additions and is not a finished product. Also to work well the server, when Rokus are being used, must be pretty powerful or care must be taken to make sure the media files are in a format that direct plays on the Roku.
I guess the Raspberry PI would be my second choice and the PI has the advantage of direct playing a LOT more formats.
Having said all that the real highest quality and most versatile setup will always be a dedicated PC running just about any client with a remote control of some kind and the server running on a different PC. While that setup is the most versatile it is also the most complex to set up and to maintain.
So the answer to you question is the same as the the answer to the question: What kind of under garments are worn by the majority of the Supreme Court? Answer: Depends.
Based on what counts for me:
Best interface/navigation: Web app then Windows 10 app
Best for my setup: Windows 10 app
Best picture and audio in all of my media: Plex Media Player
But I’ve never used a Roku or other dedicated streamer.
based on my experience Kodi on Openelec with Plexmbc (which i have now replaced with kodiplexconnect )
Best for ease-of-click would be for me the Roku. You can use the remote without looking at where the buttons are.