Openelec is a Linux OS that runs on the Raspberry pi that has TVMC/Kodi built into it. Upon install it has none of the repositories you need to watch movies. You have to manually enter those. There's a zip file I have with the top repositories(at that time) and I use that. To be honest..Genesis, Phoenix, Icefilms, Sportsdevil are all you really need. Unless you're into International, Anime or things like that. On Sunday's, I have access to ALL the football games. Even all the PPV events.
Yes. I did have it using wireless with a USB stick I put in the 3rd USB spot, but it would be choppy at times. Needed to buffer. It was annoying, so I ran a cable directly from the Raspberry pi to my router. Works great now.
Since I started this, I shutdown my 2TB Plex server. No need to deal with torrents and store locally when any and everything I want to watch is in Kodi.
I even have it running on my Mac. I use this when out or in my bedroom at times instead of the firestick. They tend to be choppy as well. I run ethernet to Mac and HDMI to TV. Works great.
What it looks like
http://img.photobucket.com/albums/v640/CLovaR1/IMG_20160113_103639_zpsdgztacir.jpg