I'll chime in what I can, having done legal studies 3/4 (albeit didn't try until the exam due to ignorance of the VCE competitive system, thinking I was doing well with A's).
A lot of people say legal studies is a rote learning subject, and while I believe that's true for some of the course, such as the court hierarchy, I found most of it was applying common knowledge - for example, evaluating various topics (Parliament as a law maker for example), the strengths and weaknesses presented made sense when you thought about them (members elected to represent people, can pass legislation quickly, but they aren't always sitting etc.) In saying that, a good memory will help with legal studies, but I don't think it'll guarantee a good mark simply memorising all the information. You need to know how to answer the question asked and how to structure your essays.
It is quite a content heavy subject, but I never found that bothered me despite always thinking it would early on in the year - if you split up the topics you learn through out the year and organise all your notes, the large content load won't present much of a problem.
I went into 3/4 legal with a 'meh' attitude (mostly attribtued to being in year 11 and not really aware of the importance), however once you get your head around the content (which is rather easy, in my opinion) I found it quite interesting to learn how our system of trial works, how Parliament operates etc. - you can apply the knowledge learnt to the real world. If you're interested in learning about Parliament, our Constituion and our rights (and how they're protected), civil and criminal procedures (which might sound mundane but are quite interesting), I recommend you take up 3/4 legal.