[wrxtasy]

Just off the top of my head, C2 vs RPi3

C2 running Kodi Krypton:
- up to 4K HEVC (H265) Hardware decoding
- HD Audio Passthrough
- Proper Hardware deinterlacing vs Hybrid on the RPi3
- No need for mpeg2 or VC1 licenses
- Faster eMMC Flash memory available
- Faster CPU
- Faster DDR3 RAM
- 2GB RAM vs 1GB
- IR receiver built in
- GigaE vs 10/100M Ethernet
- Packaged with a decent heatsink
- Dedicated USB Controller, Bus bandwidth not shared with Ethernet like the RPi3
- Dedicated power supply not needed, even if Overclocked

RPi3:
- 1080p 3D Video Playback
- Mainline Linux Kernel if you want to connect all manner of modern Perhipherals
- Bluetooth built in
- 2.4 GHz WiFi (useless in a crowded RF environment)
- shared USB2 / 100M Ethernet bus with 11MB/s bandwidth limitations. Not so good for a File Server / Mini NAS.

Not caught up.
I would say surpassed if you don't need 1080p 3D and only want to playback media.