The return channel (ie two way as you call it) ensures reliability. If you only have one or two (or maybe a few more - depending on how often they send) sensors etc using the system then this will mostly be ok. If the data can get lost and it doesn’t matter (which might be acceptable for a simple temperature sensor), then again, it might be ok. However if you want to ensure that reports are received, then you need bidirectional communications.
Simple sensors like the 433Mhz devices certainly have their place, but also their limitations. I personally used them for quite a while in the past, but ultimately they were not reliable so I moved to other systems. For your use case, they might be fine of course
I’m using a couple of TFA 30.3133 sensors (cheap, very reliable, 3 channels, option: external temperature probe; old model, might be difficult to source) - and there are use cases that (AFAIK) cannot be implemented with ZigBee due to lack of availabitlity of commercial sensors, e.g. monitoring of pool temperature.
My guess is that any mains-powered zigbee devices will do.
Do yourself a favor and get zigbee certified devices
(If someone read this and still use the Bitronvideo stick, upgrade the firmware on it!
However; a newer stick with a newer chip and firmware is the longer term solution)
I purcased exactly one of these Aqara temperature/humidity/pressure sensors to test out.
That one got stable when there was multiple (stable!) devices in the mesh close to it.
I will not purcase any more of them. Like @matt1 I will see if the Sonoff ones are more suitable. After some quick tests, it looks like they are a better choise.
