Studied alongside full time work for about 2 weeks then studied full time for 4 days and passed first time with 90% and 26 mins remaining (after I stuffed up an early PNR which I had to nearly completely redo that took around 35 mins) using the Rob Avery material. Late Jan 2014.
I found most of my answers to be between 10-30kg away from a CASA answer (both under and over) and the spread of answers was 250kg or more IIRC.
I actually found the PNRs were the part I most consistently got right in the practice exams. Not sure about other methods but the Avery one seemed to work well for me.