I have elastics right now to correct a class II overjet and an overbite. In addition, I HAD tiny elastics to correct something I can't quite understand in my 2nd molars. elastics from top to bottom on both sides. I didn't really notice much difference, but my ortho was happy! That's all that really counts, right?
I also tend to take them out and leave them around when I snack and forget to put them back in. If it were one of my KIDS doing this, I would be REALLY irritated, but it's me so it's okay!!
On a side note, I just spent a week being a councelor (with my family) to middle school kids at a summer camp and so many of them had braces and quite a few of them (even boys) would tell me about their elastic configurations and how long they had to wear them. It was really sweet.