this is the different between Android and iOS, which i told you previously... hahaha
if you are on stable rom and you want the dev access, just keep pressing on the Android / MIUI version (under Settings > About phone)
it will popup either the Jelly Bean or showing you "you now have dev access"

If you want to flash it from Stable to Dev Rom, then you have to download the developer rom from the en.miui.com website > WCDMA >

As per front page info:
1. You have preroot accessibility. No need for manual rooting steps. Just go to permission and enable it
2  Kit Kat 4.4.2 ready, all the bells and whistles that make kitkat great
3. Ability to install google camera
4. improvements/changes/updates over current stable JB based rom. But still have bugs, hence dev rom.

very high? not high only meh? no force close problems...