FWIW I can confirm, having experienced hospitalization in the U.S. - with top-tier Blue Cross coverage - and later in Australia as well - the ordinary everyday Medicare system - there is no real difference in the quality of care.
The equipment, the people, and the access are all very good in both countries - assuming you have insurance in the U.S., and I'm comparing major cities to major cities here of course.
What's dramatically different is the cost, and the level of paperwork. In America we were snowed under for years with insurance company statements and bills from a dozen providers - we ended up just sorting them by color and then weighing them... and we had to pay thousands of dollars out of pocket after Blue Cross was finished.
In Australia, you pay maybe $80 for a doctor visit, and get some of it back from the government Prescriptions average $10-$20. If you go to the ER and get admitted to a room, you have to pay $6 a day if you want the TV to work. And I think you sign like one form on your way out. You never hear from them again.