Well! After almost exactly 1 year, here I am with some news! Heheh
I'm still using my MPAI 809T MTK6582 bought on AliExpress, I've modded it, flashed uncountable ROMS, risked to break it tons of times (and BRICK it aswell) but hey, STILL PERFECT AND RUNNING.
I also tried the rom with KitKat from NeedRom, it would be nice if you could somehow pass the external SD restrictions, also Link2SD won't help you.... in the end yesterday night I switched back to the 4.3 STOCK (customized by me with personal Boot image and animation, and tweaked with Xposed and Gravitybox)
Thanks to this Phone I learned how to use SP Flash Tools, MTK Droid Tools and SP Multi-port Download Tool, I learned how to backup my NVRAM, restore IMEI, root almost any MTK device and to love chinaphones
Although, I have a problem at the moment. After flashing the rom today I noticed the weirdest thing.
I can receive calls, send SMS/MMS, data connection works fine but for some reason I cannot get the dialer to make calls.
It's not a SIM issue i thing, it's litterally the dialer that won't send the call. Do you think that flashing another dialer.apk from another stock rom (maybe 4.2) would be a good idea? Also, if you have any suggestion, let me know.
I think I will also write someday a guide called how to optimize your MPAI 809t, where I explain how to root it, install CWM, use MTK Droid told to backup NVRAM or patch boot.img and recovery to get root access and wich app to safely remove and install to get the best out of your phone.