I got my braces on July 3rd, and I have to say the spacers hurt way more. I guess it's different for everyone, but by my fourth day with braces, I was already breaking the 'rules' about food. The spacers hurt until I got them off (about two weeks). And they were very difficult to get used to.
I have noticed some major differences already. There was one tooth on the bottom that the spacers caused to be crooked. After about a week, that tooth was perfectly straight.And I just keep reminding myself that every day is one day closer to a straight, un-braced smile!