Hey, no need to be so hasty... not all sellers advertise and sell android boxes pre-configured... I myself have bought a few and all came as stock firmware. I personally even prefer factory resetting first.
What Minix box model? Since you just got the box, here's my advice to you.
*Download and flash the latest firmware for your device. Do a hard-flash with a PC and not the USB/SD-Card method as this ensures everything is setup nicely.
*Don't touch the pre-installed KODI by Minix. As that particular version has been optimized to your box's specification.
*Launch Google Play Store, download & install the latest KODI (V15.2). Don't worry, it won't overwrite the pre-installed KODI app.
*Manually configure and install addons. Its more fun this way as you only install things YOU want and can keep track of bugs.

For tips and tricks... Start with this thread... There are TONS of good info on here....

XBMC = KODI.... History... Name change... Same guys...

2mbps is min required.. 4-5mbps is very good already (if no sharing with many users).
Kodi (or more accurately addons like Genesis/SALTS/Phoenix) depends heavily on the sources.

Have u tried the latest Exodus? I just tried for few days and its really good. Particularly sources from Dizilab i can run 1080P smoothly on Unifi 5mbps.

I dislike iFlix becoz resolution so low its like watching on 320p or lower only..plus the content so outdated and not many.
Netflix still ok but then why pay when i can use free Kodi happily?

Im using Trakt manager.
Just add drama/movie into collection and it will load the list on any box/device automatically.
It even has "watched history" so i dont need to keep remembering i watched until which episode.
Lazy to try other apps. I prefer simplicity and also i found the Genesis/Exodus UI pretty comfortable and simple.
Unlike Salts and Phoenix i dislike the setting.

note there are 2 "adrians" - super adrian and adrian super tv.

the latter is far better than the former.

the one i got from superbox repo is working, very good, all categories.

sports - all in 1080 or 720.

Why don't you install it and see? 

Ding Ding... That's why, it's called a cat and mouse game.. You want stability & reliability? Astro and legal alternatives - - - - - - >>.