Hey there,
Don't know if you're still deciding, but for anyone else who happens to be asking the same question, hopefully my advice can help.
I'm doing both legal and revs this year (and I did history 1/2 last year, although it's definitely not needed to do 3/4).
Legal studies is a good subject, the course gives you a really solid knowledge of the legal system and the information is simple, straight-forward and answers pretty much any questions you have about the legal system. It is essentially a rote subject, which I suppose suits different people in different ways. You'll have to learn a lot of definitions, and know how to explain a lot of concepts. That being said, there are 'evaluate' and 'critically evaluate' questions (although in reality, the answers tend to regurgitations of pre-learned pros and cons lists) and you will often be thrown case studies to reinforce whatever you're learning. Overall, it's not particularly hard to do well in legal as long as you have a good memory and you're prepared to sit through a few boring concepts.
Revolutions is my favourite subject. Although there are some elements of straight content memorisation (i.e. dates, details of events), you'll never have to regurgitate any definitions or explain standalone concepts. Instead, it's focused far more on evaluating (i.e. making a judgement) and demonstrating your understanding through appropriate use of historical skills (e.g. use of evidence, historiography, etc.). On the other hand, it has far more content that the vast majority of other subjects (in my opinion, you could spend a year just doing one revolution) and the level of sophistication in writing is far more difficult to reach than it is in legal studies. But do note that writing skills in revolutions often translate well to English/literature - revolutions encourages you to give your writing a voice and lets you develop your own opinions. Plus, if you do English, information from revolutions can be used as evidence for expository or persuasive pieces in AOS2 (creating and responding). So overall, revolutions is a really fun, interesting subject that you can immerse yourself in and get a lot out of. If you liked history and/or other humanities in past years, revolutions is the perfect subject for you.
So in sum, if you need a subject with relatively easy marks, legal studies is the right choice. But if you're willing to put in the work, then 100% choose revolutions.