I have a GPD XD loaded with over 50gb of roms/emulators. I use Nostalgia on it because it runs very well. I recently bought a MiBox3 and can't decide which frontend to use. I tried arc browser, but the cache for some reason after scanning all the roms, was huge (Can the cache be set to use the ext usb?). I was wondering what your opinions are on the 3 frontends and which one you use/prefer for an Android TV.
Arc Browser all the way.
You can set the data directory to be any location. I have mine to my SD card on my first gen Shield. You can change what is downloaded, front cover, back cover, fan art, or nothing. If you are downloading all of them the file size will add up.
I use it because the Dev is responsive and very helpful. Also, it is customizable, great interface and just works well.
Support forum: https://forums.geforce.com/default/topic/874247/shield-tv/arc-browser-official-support-now-available/80/