In the past I have used an extremely detailed conky to view system stats, then when I moved to awesomewm I used the default bar to view cpu, network, and memory information.

Now I don't have a bar at all. The only notification I have configured is for the battery, it displays at 50%, 30%, then less than 10%. This is achieved with a script checking the percentage from acpi output and notifications are done with dunst.

For anything else I would use the terminal.