Oh wow, was yours a special case to only need less than a month from application to approval?we applied 3rd August 15 , email request 6th August 15 Visa approved 20th August 15, we applied online too
Our previous Visa was PMV300
General Info: we applied for 820/801 Oct 2014, been waiting and fingers crossed to hear from Immi soon.
The scary thing in the back of my mind is that they can reject you without contacting you for more information first.
Edit: Nevermind I saw that you were on PMW300 prior