Healthcare is one of those areas where your experience varies dramatically based on how rich you (or your employer) are. I had nothing but good experiences when I was on Google's health plan - basically walk in to any of a number of top-notch, very wealthy clinics, don't pay a cent, get great care. Ditto when I was on my mom's government-employee plan. I was hospitalized with an acute kidney infection when I was 15, one that would've killed me had I lived 50 years earlier. Immediately got referred to a top-notch children's hospital, attentive doctors, pumped full of antibiotics and made all better again, and my family didn't pay a cent of what would've been a $200-300K hospital bill. Similarly, my dad's hospitalization at the end of his life cost close to a million bucks, of which we didn't pay anything.
At the other end of the spectrum, if you don't have health insurance, you will be bankrupted by the slightest medical emergency. You'll get care, but the doctors generally won't care about you. Oftentimes you end up going to hospitals that are poorer, with more overworked nursing staff that more frequently make mistakes. Even having private health insurance these days or a HDHP from a smaller organization still is a much lower level of service, with much higher amounts paid out of pocket. When I left Google I bought a private individual plan from Anthem, the same insurer I had at Google; despite it being the same company, my existing doctor wouldn't take the new plan, and I couldn't even see the same doctor I'd just waltzed in to see on Google's plan without paying $400 out of pocket or so.
Much of Obamacare's achievement and Obamacare's pain comes from being an attempt to spread the misery around, so that we don't have a caste system for healthcare in the U.S. It's meant that 20-30M people who were previously unable to see doctors at all now have basic health care, but it's also meant that many people for whom health care used to be completely covered, free, now have to pay something close to the real cost of their care, and they're finding out just how much the experience sucked for the rest of America.