Haha I'm not unique, there are several BoSers around here who do the combo actually, including one of the benefactors - cherryblossom so I'm sure there are others who might not mind giving their opinions on the combo if asked. I know tezor does the combo as well, not to mention Lhyviathan, fine ambiguity, minushuman and at one point KFunk did, so maybe one of them will wander in at some point if they see the thread.
But away from the me basking in my own greatness theme, I chose my 4u of eng, 4u of math and 4u of science(used to be 6 but I dropped physics before trials yay!) mainly because I was passionate about everything and I could *not* choose between subjects in fact I wanted to do Ancient + Ext Hist as well
, however I found that the hours would not support that no matter the efforts I might put in and neither would my teachers regardless of leniency so that was 3u of history out the window. So time management was a huge factor if that hasn't been made clear already, you *have* to devote time to reviewing and going over your maths all the time - not to understand things, but so that you can compete. And then there is the monster project that is EE2 - it sits at the back of your mind all the time(and if it doesn't then it should), and whats difficult about this subject is its the only one where you can spend hours at a screen getting *nothing* done and thereby interfering with all of your other subjects and subconsciously making you put EE2 last on your to do list.
That said, they are both *fantastic* subjects in their own way - they(and the other extensions) challenge your ideas in ways that the 2u HSC courses simply don't and I recommend everyone at least look over an extension subject at one point. Just remember not to tackle something that is *too* much for you, because you will burn yourself out and be useless in your other subjects. You also shouldn't take on subjects because of prestidge or scaling - there is nothing more unfortunate than seeing someone in a 4u class who is there because they think it makes them look smarter or because their parents think so and then seeing them get burnt by assesments and slowly drop to general/standard. Anyway my rambling has probably gone on long enough lol.