Hello
Hey lara,
well i did postmodernism AND 4 unit this year, so think yourself lucky that i'm here!! (hehehehehehehe just kidding)
anyways postmodernism is a really good unit. It's interesting and fun at the same time! yoou'll really like it. Postmodernism claims that there are no absolute truths: just multiple perspectives. Now it might sound weird but you'll catch on very quick in the first few lessons. You'll study things like why authors give marginilised characters voices, and how creators of film have changed TRADITIONAL filmic conventions.
it's hard to explain but basically the movement changes and challenges traditional ways of doing / presenting things.
as far as difficulty, there is very little. serious!! but i spose it also depends on if you like the unit. i found the course quite simple, its only a 1 unit course so there isn't that much work. i found advanced english harder than 3 or 4 unit!!
some parts of the course are a little challenging such as the creative writing part, but it's gennerally doable.
4 unit? choose it, you'll like that course aswell. you'll need a little responsibility but it's all freedom. you can do pretty much all you want. I loved it, but it got very draining towards the end, and i found i was working my arse off the last week
anyways, i hope this helps, good luck with whatver you choose!!
Cheers
Coffee_Fan