The pro of Broad Spectrum is that you get close to full benefit of everything in the cannabis plant with out the THC. This means there will be no trace of THC in drug tests as well.
The con of Broad Spectrum is that you will not get the extra benefit of THC.
The oil is taken by putting the desired amount under your tongue and holding it there for 60-90 seconds. This is the most beneficial way to get it into your blood stream for longer lasting, stronger effects.