My experience was very different. In January-February this year I had to visit (unfortunately) both the Emergency Room in NYC and the A&E in London. While the quality of the medical equipment in London matches the one in NYC, the understaffing is much more severe. In neither place was my wait time only 10 minutes, but in NYC I had to wait for about 1 hour (including paperwork), while in London for about 6 hours.
I talked with other people in London about my experience that the medical system is severely understaffed, and all agreed. On the plus side, I did not have to pay anything in the UK (they didn't even care that I was not a UK resident). In the US I had to pay north of $1000, despite having insurance.