The Buzz is EXTREMELY easy to use immediately. Charge the batteries, put them in, screw on whatever compatable carto you have and sit back and enjoy. They are set at the factory for 4.5 volts. That will work great on any cartos or atomizer you have except for the LR or low resistance atty's, which are designed for 3.8 volt batteries, like the KR808's and simply are not needed or recommended for quality VV Mods like the Buzz or Infinity.
Now, you don't need a voltmeter (although it is nice to have, but hardly necassary) to adjust the voltage on either the Buzz or Infinity. You can just tweak it as you go, and see what works best, but honestly, you can just vape away at 4.5 volts without ever changing a thing, and your vaping experience will improve 500%.
People think mods are complicated. The Notcig PV's are easy and simple to use. The only thing you are missing is more flavor, more vapor and better TH. Been there, done that.