If you don't think that you'll like it, I wouldn't do it. I absolutely loved media, but there are a few problems with trying a subject you don't love. Personally, I focussed on my 3/4 subject, however I didn't love it as much as I did originally, so it meant I didn't reach my full potential and as a result, my study score was only a 32. That said, having a teacher who was fluent with the course would have helped. If you're prepared to work at it, then do it, however if you aren't a creative person, you might struggle a little. I know when I created the short films for class, I was always the one in my groups who came up with the ideas and the one who had to organise everything, and as a result, my group members lost marks for not contributing. It does scale down quite a lot, but your SAT halfway through the year is an extremely important subject, so I would suggest questioning yourself on whether or not you can balance creating a film/series of photographs/visual mixed media composition and balancing the rest of your subjects in 3/4 media. Though, by the sounds of it, that's a while away for you, so definitely focus on your 3/4 subjects, and keep media in mind if you really want to do it, but definitely don't if you aren't going to work hard.