My only personal experience in a British hospital was fine. They saw me promptly, the treatment was fine, the free meal was typically British.

I've been twice to Danish hospitals, and I think the experience is very comparable. The staff in Copenhagen seemed kinder (a bit more time to reassure the patient etc) but otherwise there wasn't much difference.

I trust both countries in 2015, and Denmark in 2020. I don't know what's happened in Britain since 2015. My family aren't complaining (at least, no more than the usual British amount), but the British people keep voting against their interests.