My fellow Americans. Maybe you've seen those ads featuring horror stories from the British national health system. You know, the ones where a British cancer specialist and three patients talk about the perils of "government-run healthcare in Britain". Their stories may all be true – no health system is perfect, and the NHS, like any large organisation, is far from perfect. But as someone who has been on the receiving end of healthcare in both countries let me tell you why I thank my lucky stars for the NHS.

We have three children. The oldest was born in New York at Beth Israel, an excellent hospital, though like most busy big city hospitals you'd never mistake it for the Waldorf Astoria. I was working for a daily newspaper, with a good health plan, and mother and baby were healthy, so the co-pay was only about $1200 (on overall bills of about $6000). Our two youngest were born here on the NHS, at University College Hospital – an equally superb teaching hospital with plenty of specialists on tap. The first time we decided to splash out on a private room. By the time our youngest was born we were veterans, and opted for the ward. The £120 for the private room was the only bill from both pregnancies, even though our youngest (now a very robust 10-year-old) had what the neonatologist thought might be a problem with one lung, meaning he had scans and tests and procedures before we were allowed to take him home – and follow-up visits for the next few years to make sure he was developing properly.

Karol Sikora, the cancer specialist acting as the frontman for this campaign, talks about competition and choice, as if healthcare were just another consumer good, like a mobile phone or a cheap airticket. But for most of us healthcare isn't a luxury. I grew up in a home where the cost of healthcare was a constant worry – I still don't know how my parents, a social worker and a kindergarten teacher, managed the expense of my own childhood cancer. I do know that when, as a college student, I finally qualified for free dental care, I had 10 cavities filled at once.

So I know exactly how much it means to live in a country where no one worries that if they get fired they'll lose their healthcare – and no parents have to choose between food or medicine for their children. Yes there are problems: the UK's cancer survival rates are poor – below not only the US but also countries like Sweden and Norway with extensive national health systems. Any national health system involves an element of rationing – and with pharmaceutical companies driven by profit that means some medicines will be too expensive for the taxpayers to afford.

You wouldn't know this from Dr Sikora's description of the NHS as a government "monopoly", but Britain is a mixed economy, not a socialist dictatorship, with a thriving private healthcare sector for those who want more than the NHS can offer. I've used it from time to time myself – to get more time to talk over my treatment options with an opthalmologist, and because it didn't seem right to let taxpayers bear the cost of my wish to run a faster marathon.

But as someone who could probably be described as a mild hypochondriac – meaning I tend to phone my GP with the first cough, rather than waiting until I need an ambulance – I know which system I'd rather have. Anecdotes aren't evidence, and the experience of one pushy American is no more (or less) valid than someone whose cancer became terminal while waiting for treatment. What you can't know unless you've experienced it, though, is what it feels like to know that your relationship with your doctor is not in any way a commercial transaction, or that when you are referred to a specialist for tests, its because you need the tests, not because tests generate income for the practice. They don't pledge allegiance in this country, but while I consider myself an American patriot I'd happily pledge allegiance to the NHS and all of those who work in it. To those Americans worried about "British-style" healthcare, I can only say: you should be so lucky.