Just read some specs about the new ASUS Tinker Board. It has the size and connectors as the RPi3 but 2GB RAM, RK3288, Gigabit LAN (hopefully not connected by USB), option to use an external WiFi Antenna and 4K output using HDMI 2.
I didn't get much details about the architecture but in the german forum they claim that the GPU might be not powerful enough for 4K and lacks hw-acceleration for some codecs.
I also didn't get any information if and how CEC is supported,..
Asus Tinker Board: der Bessere Raspberry? - Raspberry Pi - Kodinerds.net - Deutschsprachiges Forum zum Kodi Entertainment Center
ASUS release their Tinker Board Raspberry Pi competitor | Systems | OC3D News
Rockchip RK3288 - Wikipedia