What are the pro’s and contra’s if you compare Point to multipoint in 802.15.4 modules and S3B Xbee-Pro 900 HP?
Are there differences in realiability and speed?
Thanks in advance for y advice.
Wim
Yes there are differences. I would strongly recommend you read over the throughput testing sections of their respective manuals.
Keep in mind that that 900 HP can’t be used in all parts of the world. It is mostly designed for the America’s.
That answer was really helpfull 
The 802.15.4 currently supports a throughput of 80kbps
Supports DIO line passing.
The 900 HP supports a throughput of about 105kbps and doe snot support DIO line passing.
The 802.15.4 uses an external VREF for ADC conversion from 0 - VCC. The 900 HP uses an internal VREF of either 1.25 or 2.5V.
The 802.15.4 is a peer to peer, point to point, point to multi-point product. Does not support OTA updates.
The 900 HP supports Peer to peer, point to point, point to multi-point, repeater and Mesh networks. It also supports OTA firmware updates.