I would like to be able to give a certain user permission to just parts of a device, like say one port on one switch. I have some core routers with a lot of customers hooked up to it. We measure those ports for bandwidth and similiar. I would like my customers to have their own login and being able to see their bandwidth graph for just their port and not the entire device.
Today we use Cacti for this, to be able to use Zabbix we have to add the switch as a new device called 'SwitchXX - customers XX' and just monitor their port on this device. This isn't happening with a few hundred customers.
We also host a lot of managed Linux/Windows servers, today we can only give customers read permission to the entire server in Zabbix. Maybe we just want them to see disk/cpu/load graphs and not triggers/items for free. This isn't possible either and the huge lack of permission granularity is a big show stopper for us implementing Zabbix instead of Cacti. Which we really, really want.