I updated it like a real Mac, using the Installer from the App Store, even though it took long (quite an hour or so), it works. What doesn't work is Bluetooth. I've already tried many things, but nothing helped and honestly I don't really need it, but you should keep that in mind. The first thing I've noticed was the pretty long boot and shutdown time (3 or 4 times as long as it was under Mojave). The battery seems to be okay, not much better or worse as ist was under Mojave.
I am using the BCM43225HMB (branded by AzureWave)
I can't help you with the Bluetooth problem (it seems that almost everyone has some kind of problem with Bluetooth),
but I may can help you with the sound. In my case, the update changed the injected Audio-ID. What I did :
1. update Apple ALC
2. changing the injected Audio-ID back to the number I used before updating
3. reboot
After that it worked.