The Legal Studies course, while useful in general if you wish to study for law, is by no means critical or crucial for Uni law courses.
That means that the content we study in legal studies is often more interesting compared to the University Law content as the HSC syllabus. This is because, in general, the Board of Studies tries to make subject syllabi as interesting as possible to encourage students to take that subject. The content you study in Uni is often more boring and monotonous due to the nature of legal studies as a whole. You need to be able to know the law inside out for most areas and consequently Law is often described as REALLY boring. Especially, law regarding property and in general private law is often quoted as dead boring.
Also as in most subjects, the HSC course is WAY more interesting compared to the prelim course.
Uni Law requires TONNES of memorizing so if you arent really into that, then i would suggest you go talk to a Law student at Uni or a legal practitioner and ask them how studying law is and consider their perspective as well. Ther is also the Law Admission Test(LAT) that a lot of Uni Law courses require to be taken so if you want to do law, you pretty much need to prepare for the LAT.
Hope that helps!