OEM headunit has no comparison with aftermarket android panels. Aftermarket panels are oversized. It obstructs ac vents. The tesla style thing has the Aircon /climate control in it. Its not wise to mess with oem system.
The oem backview cam has an excellent result wether its day or night. The aftermarket cam wont have a such a quality. Moreover the aftermarket wiring is always fussy.. it looks messy and joints become corroded after sometime and the camera stops working which makes u looking for some ustad ji.
The sound quality of oem unit is very good. It works well with usb hooked in the ipod slot instead of smart usb slot.
Lastly, if possible, go through the android interface of oem headunit and the chinese panel. The user interface of oem headunit it simple and decent. While that of a chinese panel it feels like a china mobile