It's entirely down to your strengths. You will likely have to revise more, yes, but that's the nature of A-levels. However if you're finding things easy at that current level of revision, you know you're more than capable.
For example, if I was to study Sociology having no interest or desire to learn more about the subject, I would say I would have to study more than the average person, just to overcome my own 'barrier of entry'. However in your case it could be completely different.
The initial increase in expected knowledge and work given could be a shock, or it could be something that comes naturally with your revision at GCSE. In my case, I didn't want to do A-levels and didn't care at all about GCSE's, so I never opened a book as soon as I got home (For GCSE's), all I did was pay attention in class (For the most part). Following this, when I started AS, I noticed immediately the increase in workload and the expectations teachers have of you. So to me, the jump was significant, but again, entirely objective (Based on past revision and subjects).
I wish you the best of luck!