Stable Firmware build for R7800?

Hnyman's 19.07 branch build (r11333) (Build for Netgear R7800) with mainline Ath10k wireless driver and firmware (NOT CT driver and firmware) works really well for me. Probably for many others too.
It is effectively a slightly newer than the "official" 19.07.7 stable build with several nice tweaks targeted to R7800. It is a mature build.
Apart from the Ath10k driver/firmware you may also look to enable Adblock, irqbalance and "performance" governor CPU profile.