I think Digby's take on ACA is good. Yes it will likely be, in the net, an improvement over the current system. And, yes, people who were unable to get insurance now will be able to and people buying insurance on the individual market will have better plans. But it's still the case that some people who really don't make all that much money are going to be paying more than they can really afford for a health care system which is still far from perfect.
The younger, healthier, more well-off aren't that well-off.