I use the VIM3 now daily.
I can say I almost always have this with USB3 devices that wifi stops sending packages.
It did happen a few times that USB3 was working and wifi together. But this is rare.
For that I use a wifi dongle in the USB2 port. Then there’s no problem using the USB3 port.
Also when using a 2.4Ghz dongle in the USB3 port the on-board wifi slowed down a lot.
Almost every SBC with USB3 has this problem. The N2 has it when using 2.4Ghz devices in the USB3 ports, the NanoPi M4 has it when using 2 ports next to each other(not crossed)
Thermals are not really an issue. It does throttle without a fan when maxed out for long.
But it is very useable. You can clock it lower if you don’t want it to throttle. It’ll still be a beast.
A bigger heatsink would be great.
But even with a fan at 3V it’s sufficient to keep it cool. Compared to any raspberry pi that’s very good.
Overall I’m very happy with the board. I’ve also got the Odroid N2 too. That one has a lot more issues, and the support from Hardkernel has become a lot less. Last image is still from March, full with issues.
The NanoPi M4 is all-round very good. Good heatsink, best wifi of all SBC’s, and good USB3 ports.
But the Khadas VIM3 is a lot more powerful and uses a lot less energy. So it’s all about what your use case is.