I first got my braces about 7 years ago, so I have a feeling they are very different now from what I got back then.
Because the main problem I had with my braces was the metal. See, I had them on the top and bottom, and the metal things out front tended to jab and cut the insides of my lips. They gave me this nasty wax stuff to put on them to cushion it, but the wax tasted awful and always wore away pretty fast. So I just dealt with it. Finally, I think I either developed thicker flesh there or just habitually began to keep my lips in a different position out of defense because it stopped...after a few months.
But as far as tooth pain, I never really felt any at all. However apparently I was pretty unusual because I never needed rubber bands, which I hear are a pain to put in and take out (which you have to do every time you eat, or so I've been told).
And if you get a retainer, that isn't very bad at all. But it does get pretty nasty and smelly and you will sound as though you have a severe speech impediment while you're wearing it.
Again, orthodontic technology has probably vastly improved in the past seven years, but that was my experience. Good luck!