I am 2009 HSC student and
I really advise you to do 4U maths
Reasons are:
1) scales up very high
2) Fun
but I will not advise you to do it if you are not good at Extension 1 maths
You said you are getting 95+ in 2U, but ALL extension 1 maths students in my class
(approx 27 people) got above 95 in 2U which shows that in actual final HSC exam, there will be many people getting ABOVE 95 and there was actually many got 95+ in 2009 HSC 2U maths exam. This means that you are not going to get scaled up unless you get more than 95+.
IF you are good at extension 1 maths, you can go on reading
Extension 2 maths SCALES UP SO MUCH that you will cry
The BoS will not give you the raw mark but I can guess what raw mark I got
I got around 72% for my extension 2 maths 2009 hsc and my final result was
92%.
My friend says he might got around 65% and he got 90% for the final result.
The school mark is not that important UNLESS you do well in the final exam and you are top 10% of your class (I was rank 2, and the guy got 65% was rank 3).
This greatly contributes to your ATAR and also if you are aiming for 90+ ext2 is recommanded,
95+ I think you Need to have extension subjects such as english or math or wtv
for 98+ you Must have an extension subject and the easiest one should be math ext 2 or eng ext 2
of course, you need to do other subjects well too but if you do ext 2 math or english, the chance of getting 98+ ATAR WILL increase greatly
I need to tell you one more thing that
extension 2 IS NOT an easy subject, seriously.
so in school (of course depends on your school level), if you are getting around 50%+ ( for me my average ext2 mark was 60% in school), you SHOULD NOT drop it.
you at least need to use 40% of your time on maths if you want to do 4u
not only for you, but that's true for everyone. Many will agree on this unless they are genius.
You think ext2 is hard but you need to know that it is hard for everyone so please consider taking the course and not give up if your ext 1 is going well.
Also It saves time in Uni as well because 4u math is uni level maths