Unfortunately it costs far more than the life cover and doesn't cover half the things that people think it does, or if it does cover a condition that you'd expect it to then you need to make sure you're aware at what stage it'll cover you i.e. Most policies cover breast cancer, however if you get breast cancer it doesn't mean it automatically pays out, you'll tend to find it will only pay out if it's above a certain Grade/Stage of cancer, and the same goes for other illnesses that they state they cover.
Income Protection policies are an alternative, still not the cheapest but pay a monthly benefit to cover your living costs if you can't work and that incorporates much more minor things as well as serious illnesses. If you broke your legs and were off work for 6 months a critical illness policy isn't gonna do anything, an Income Protection policy (Full policy not one of the budget ones) will cover up to 60% of your income and be much more useful in those circumstances.
Funnily enough I had an email today to say a client has been paid £300k on their critical illness policy due to cancer diagnosis, invaluable cover if you can afford it and genuinely need it.
