Why use UserParameters if I can live with system.run[]

With UserParameter, I can gather custom information for the Zabbix Server.
By why split configuration in two places if I can make it work with a single configuration which is nicely stored in Zabbix Database?
I tend to keep all my configuration on the server side and for remote information, gathering try to use system.run[] functionality as much as possible.

Turns out there are still advantages to use UserParameter:

• I can execute one-liners where the lenght of command is longer than 244 symbols
• Don't want to keep passwords in the Zabbix Server side
• Necessity to use key with different gathering interval. for example net.if.in
• Less escaping symbols like square brackets. For example it is hard to escape egrep -o "[0-9]+([,.][0-9]+)?
• Can hand over parameter to the key file. See mysql.size[*] key in userparameter_mysql.conf
• Increase security by disabling RemoteCommands= in zabbix_agentd.conf