Well, I did History Extension last year and as you said, everyone's opinion is different however I can only give you my own opinion, so I hope it helps!
The course structure of History Extension is split into two parts, the first which is titled
What is History? In this part, you will methodically and philosophically learn about history as a whole by learning about various historians. You will be able to ultimately choose which historians you want to use in writing your examination, for instance including Herodotus and Machiavelli. However, you also study an area of history in-depth, such as John F. Kennedy. I know this sounds heavy at first, but overtime it becomes apparent that these studies are not as intensive as they would be for Ancient of Modern History, since it is mainly about historiography (quotes and how historians perceive history) rather than what happened (content).
The second part of History Extension is
History Project, better known as a 2500-word essay you compile over the duration of many months researching. In this case, you are able to choose whatever you wish to research, whether it is a personality or event in history. Personally, I did the conspiracies of 9/11, so all I had to research was what historians thought about the conspiracies regarding 9/11 and come up with a conclusion myself. During the project you should receive a lot of advice from your teacher, so do not worry about it if you find you need help! This project comes in stages which guide you towards the completion of your essay. You will have a logbook where you can insert weekly entries to mark the progress of your project, as well as completing a project (basically an expression of interest to what you will be researching) and finally as many draft essays you like that your teacher can mark!
With that said, there are a few important things you should know about History Extension to aid your decision about choosing it or not. As I said before, History Extension is all about historiography — how history has been written. Therefore, you will have to know a fair amount of quotes, analyse the context of sources and the background of historians. Whether this is something you are interested in or not is up to you. As for what the examination is like, there are only two essays you have to answer, both which only apply to
What is History? Your
History Project would have been completed before the time the HSC starts.
I would have to say that I did enjoy History Extension and it ended up being one of my favourite subjects in the senior year, if not my favourite. I found that it was a subject I could relax in and calm myself from the stress of other subjects. The workload is fair and if you contribute a little time to History Extension each week, you should be fine. I would say it is worthwhile, because the subject does get attuned to your tastes more than others and you have a lot of choice in what you can do. Hence, it is also interesting in that it has so much variety.
I might edit and clear up this post later since this is what I came up with the spot.