When comparing Radxa Rock2 vs NanoPi M4, the Slant community recommends NanoPi M4 for most people. In the question“What are the best single-board computers?” NanoPi M4 is ranked 43rd while Radxa Rock2 is ranked 47th.
Ranked in these QuestionsQuestion Ranking
Pro Built-in Bluetooth
Has a built-in Bluetooth module. Meaning there's no need to buy one.
Pro Built-in Wifi wth antenna
Has built-in Wifi capabilities.
Pro Can dual boot Linux and Android
Other than supporting several Linux distros along with Android, you can also choose to dual-boot both.
Pro Provided with a clear plastic case
Comes with a clear plastic case included in the price, which is pretty useful for most projects people would use a SBC for..
Pro 6 core HexaCore, compact nvme extender, 4GB RAM
Pro Many ports
4 x USB3
2 x USB2 available via pins
PCI-E available via pins
Rockchip 3399 with two fast A72 cores. Good heatsink limites throttling.
Pro Open Source
Works with mainline Linux kernel and open source Mesa Panfrost drivers.
Con HDMI has some problems on Linux
The HDMI port has some issues on Linux, fortunately these issues are not present when using Android.
Con Bleeding edge...
To have mainline kernel requires a bit of tinkering (e.g. installing Armbian). Panfrost drivers for 3d acceleration are not mature and crash sometimes...