I had healthcare prior to the implementation of the affordable care act, so not much changed. However I did notice that all of our routine checkups are free now. I heard that, as a way to prevent disease, the act requires basic checkups to be covered. I also saw that our insurance provider lists, in their pamphlet, that they will not deny for pre-existing conditions, which was another provision of the law.
I know less about people who are in the exchange, but I work in a computer lab and I've seen several people signing up. They started the process upset (because they were required to buy insurance) but by the end of it they seemed surprised by the low amount they would be paying out of pocket. So, I think it's one of those you-won't-know-until-you-try-it things.