Good day. I have used Cacti for my data centre monitoring system since 2006. What I can say is that, the script very useful, easy to understand, easy to write the template for unknown SNMP devices or from scratch and looks nice.
Since last year, I got a problem to get a better template to monitor Juniper SSG 320-M (firewall + VPN system) and UPS Net Agent II.
Some UPS monitoring system unable to fetch SNMP data from Net Agent II and some only can get a few data. From snmpwalk I ran, the device can provide many data on utilization and health check. I found a good template for this equipment (forgot from where) but not really complete. So, I added a feature more graphs. Also, some OID were not right and SNMP fetch failed.
What the Net Agent II script can do is to monitor Battery Voltage, Frequency of the AC, Load and Changing percentage, equipment's temperature and In and Out AC voltage.
What I wrote a few month ago was template for Juniper SSG 320-M. I started to write it since the first time the equipment was installed in my workplace facing a trouble. Stop function unexpectedly. So, this template I have is to monitor 5 units of fan inside it, temperature at the CPU and in the system. I do not find any other feature I could get from the OID of this equipment. But, what I have here is fine for me.