Ok have a look at this scenario.
one of my friends goes to standard and has been working hard, and i mean hard all year improving his essays which would beat 90% of our ADV class. He came 2nd in class for standard and overall got 75 in HSC.
another friend read all the material but never prepeared shit, he also never had any supplementary material for anything, he ended up making up his supplementary and writing his essays from nothing...He was about 30th/54 in school and ended up with 80 in HSC.
my advice is take advanced english, your still going to have to write the same way and will have to know your jargon in either case, my feeling is you will find it easier in ADV as its enough to keep up while in standard you have to extend yourself above others.