The MK808 and UG802 Android mini PCs are arguably two of the most popular dual core Rockchip RK3066 based Android mini PCs. They are also among the first Android TV stick devices to feature the RK3066 chipset.
Features wise, both the MK808 and UG802 are quite similar with the MK808 holding a slight advantage over the UG802 as it comes with 8GB storage ROM compared to 4GB on the UG802. The MK808 also comes with Android 4.1 Jelly Bean while the UG802 has the slightly older Android 4.0 Ice Cream Sandwich.
Both devices enjoy great support from the open source community with many great custom ROMs being developed and released. The custom ROMs add new features to the device as well as improve stability and fix bugs. The popular Finless custom ROM is available for both MK808 and UG802.
There are also upgraded versions which add Bluetooth connectivity. The MK808B is the updated version with Bluetooth while the UG007 is the updated version of the UG802.