Congrats on your new device.. Improving user experience? That's a very subjective question as it depends on things you desire, what can be accomplished and your willingness to get your hands "dirty". Fusion is a repository granting access to addons, while mashup is an add on like Navi-x. However, MashUp has been replaced with "Phoenix" addon. There are a bunch of other addons you could install like Genesis, Icefilms, 1channel, yify etc.. Then there r themes customization for kodi and live TV streaming. Android apps like showbox.. Basically, use the search function and read backwards on this thread for more information as its all there, answered a few times already.

for yr new androidbox, some tips for u...

for kodi, get these great addons:

bbts - worldwide live tv channels
http://www.bbtsip.tv/repo.html

movies/tv shows - kmedia torrent, formerly xbmctorrent
https://github.com/jmarth/plugin.video.kmediatorrent

malaysian channels, u gotta search for posts by abemin in this thread to get the instructions and xml.
there are also some great android apps u should like too:

mobdro - worldwide live tv - news, movies, sports, documentaries
https://mobdro.com/

then are the popular movies/tv shows apps popcorn2u and showbox which u can google to find them.

honestly, after 1.5 yrs, i find myself not using kodi much anymore as the android apps combined offer more, faster and easier in navigation.

lastly, do take note of the device memory available. apps like popcorn2u and kodi with many addons can take up a lot of memory.

have fun!