Personally I found Revolutions to be one of my best subjects in my Year 12, although that may be down to having an inspirational teacher as well. With regards to difficulty, it comes down to application and memorisation. The general timeline of events will be relatively easy to remember, its just the dates and historians names that will require some tedious rote learning.
In terms of the assessment and examination, unfortunately its one of those subjects where you really need to rush with your writing. There simply isn't enough time to sit back and think or brainstorm when you're writing, as being history, there is just so much that you can write about and the limited time can make for some frustrating experiences.
That said however, I'd highly recommend doing this subject, you get to learn about some really interesting figures and events, and if you've got a few good friends doing it with you, its going to be really enjoyable.