I know Yosemite is still a beta but I wanted to give a heads up that the bandwidth counter does NOT work in Yosemite. It does work upon install but after a reboot it stops working.
For the devs, this is what I found in the console: “Whatpulse is not entitled for com.apple.wifi.scan”
It is beta indeed, but it will be fully supported in the next release.
WhatPulse includes a startup script that they changed to run as a regular user instead of root. The startup script makes sure the client (running as a regular user) can read your network traffic. Without those changes on startup, no network measurements.