Works as described with the bandwidth to deliver 4K 120Hz and Dolby Atmos. After trying a cheaper splitter from another company which was limited to HDMI 2.0, I can say that from a PC with AMD 7800XT to my older Onkyo TX-NR636 (Atmos) & Samsung 4K 120Hz TV, this splitter succeeds in the HDMI 2.1 capabilities that I was after.
PC games work with low latency 5.1 surround sound via the appropriate EDID settings and 4K HDR films and TV are output well via the alternative EDID for Atmos, in addition to the eARC output from the TV to the ARC-capable Onkyo receiver. Atmos output from games may work too, but the true Atmos output titles on PC are limited and untested for me. CEC works too The only gripe is that after turning the TV and receiver back on, the eARC output from the TV to the receiver gets stuck in PCM mode and not Dolby Digital output - something that is amended by unplugging all plugs to the splitter, then plugging all back in. I rack this up to the strange workings of eARC and ARC, rather than a shortcoming of the AX211, and am still happy with the splitter overall. Perhaps a future firmware update would help here.
I recommend the AX211 to increase the life of an older but still very capable AV receiver to match more modern TVs and entertainment sources while reducing negative impact/waste to the environment.