Simple economics has been long been built upon. It has been shown repeatedly that with our current private health care system we pay nearly double than other industrialized countries while having worse healthcare results. If you'd like I can spend 5 minutes Googling links to the studies that proves it out. However, that information has been posted in these forums repeatedly.
As for efficiency, I had to wait at urgent care for 90 minutes just over the weekend when I finally determined my breathing was bad enough to incur the medical cost. Even making as much as I do I still end up weighing my health against the time and cost. I can't imagine if I were making less and truly couldn't afford the care. I guess in at least that scenario I'd be on America's Medicaid socialized medical system.
I have had many different health care plans in the US over the years. They've all cost me a fortune (especially now with kids) and I really don't see anything better with our system than in other countries where I would pay less. It has been even worse now that I have a son with a disability which is costing us over $15k a year with out of pocket costs and premiums. But I guess Econ 101 says myself and others are doing better in the US /snark.