When comparing BeagleBone Black vs NanoPi M4, the Slant community recommends BeagleBone Black for most people. In the question“What are the best single-board computers?” BeagleBone Black is ranked 22nd while NanoPi M4 is ranked 54th. The most important reason people chose BeagleBone Black is:
There are 92 expansion pins, with 46-pin female connectors on both sides of the board with other 6 serial pins to be used for debugging.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Extendable hardware
There are 92 expansion pins, with 46-pin female connectors on both sides of the board with other 6 serial pins to be used for debugging.
Pro On board storage
Has on board integrated storage of 4GB. It can also have an SD card in addition to the integrated storage and can boot from either of them.
Pro Programmable Real Time Units with GPIO control
Real-time coprocessors allow for embedded systems control and bit-banging communication
Pro Analog Inputs
There are 7 1.8V analog inputs.
Pro Responsive, helpful online community
Pro Easy of use
It hosts a web service over USB so it is super simple to get started with plenty of source code and examples available.
Pro 6 core HexaCore, compact nvme extender, 4GB RAM
Pro Open Source
Works with mainline Linux kernel and open source Mesa Panfrost drivers.
Pro Many ports
4 x USB3
2 x USB2 available via pins
PCI-E available via pins
Pro Fast
Rockchip 3399 with two fast A72 cores. Good heatsink limites throttling.
Cons
Con Only one USB available for peripherals
There's only one USB port available for peripherals, which is a bit annoying considering how two USB ports is a minimum to have a keyboard and a mouse hooked up without having to use a powered USB hub.

Con Lack of a proper OpenGL driver
It sounds like the driver is possible, but the information is spread out over forums and GitHub.
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...
