I get about 350-400 both ways which AFAIK is what my Unifi AC-Lite tops at since it's WiFi 5 and it's only got 2 antennas and tops at 80MHz channels. I get about 200-250 on my phone (1+8T) which I think is single stream.
Everything indicates me that's as best as it can be with the set of hardware I have. Signal is solid, latency is solid.
You'll need 802.11ax and/or more MIMO streams to get higher speeds, and/or 160MHz/320MHz channels.