previously i was using this "Mijia Mi Smart Home Gateway 3 Bluetooth Mesh Hub Zigbee 3.0" with mihome app
https://shopee.com.my/Mijia-Mi-Smart-Home-G...5082.3815507160
i had a switch to turn off all downstairs light & fan. It is noticeable that the switching off process was slow and did it one by one.

Recently i changed to this "New Aqara Gateway M2 Support Zigbee3.0" and using Aqara app (cause mihome don't support this).
https://shopee.com.my/product/72563668/7462016661
I bought at RM152 from the same seller, out of sudden increased to RM335 now..
The same turn off all downstairs light & fan button react fast and no delay.

No idea it's the app or the gateway issue. I am pretty sure my automation is "LAN" and not "cloud"

If need Alexa/Google integration best to go for Tuya Zigbee ecosystem.

mine run with china mainland server, so no chance to connect to google.

doing research on tmall genie... not much improvement yet.

All Tuya Zigbee gateways are universal no matter whom you buy from. My 50 units wired gateway should arrived by this week. I also have Tuya Alexa speakers with Zigbee gateway & IR but have some limitations because not by Amazon.

Tuya Zigbee Sensors need be careful if need Alexa/Google support. I have different batches from different suppliers all not up to my requirements. Already found one that can do 100% Alexa/Google integration but too busy to nego. His price rather high. I also found a universal Zigbee sensors that can support Tuya, Sonoff & Generic Zigbee meaning Smartthings, hubitat, ikea & philips support but price of cos very much higher. Tough decisions.