You have to wear them 22 hours a day and when they're on all you can consume is water. If you eat anything, you gotta take them off first, and after you need to brush/floss/rinse. You can't just be munching on something. It's partly why I quit chewing gum and slowly reduced the tea/coffee I drink. Though, supposedly you can still drink colored fluids if you use a straw.
When you're wearing the braces, it's no big deal because they're clear and fit fine; there is only a slight pressure. But when you take them off, it's an awesome surge of pain and your teeth feel so weak.
probably still a lot better than regular braces, but still. I was basically forced into doing a bunch of dental stuff in the past year to save money.