From what I know in general, UK doctors work a lot fewer hours but also have lower compensation than doctors in the U.S. Most UK doctors work for the NHS which is the National Healthcare Service. Generally consultants (aka staff physicians) make around 100,000 pounds a year which at the current exchange rate is around $160,000 a year. Generally during foundation and residency training in the UK you are paid around 27,000 pounds and going up every year which is similar to residency pay in the U.S. However, UK doctors work fewer hours. Both professions are well respected in their respective countries. In the UK, you are allowed to enter medical school straight from high school as well as after a bachelor's. In the U.S you need a bachelor's degree.
UK - Highschool -> Medical School (5-6 years) -> Foundation Years (2 years) -> Residency (2-10 years).
US- Highschool -> Bachelor's (4 years) -> Medical School (4 years) -> Residency (2-8 years).