Nothing serious - just accompanying my fiancee who had a routine operation. But it was an interesting experience. I was actually quite impressed with the quality of care.
One of the interesting aspects of health care in Britain is that it is quite common to have private health insurance here, despite the fact that the public health care system is one of the best in the world - the care is of a more than high enough standard that the private insurance generally covers only expedited access. That is if you end up on a waiting list you get to go private, otherwise there is little point, except perhaps more single rooms and tastier food.
And despite the Conservative party and their rather pathetic attempts to use the NHS to drag down the government (not that I have any sympathy for Tony Blair, but I do have sympathy for the NHS staff that has to endure being the target of so much mud slinging) what I saw of Kingston hospital was great (except the way it looks - the architect deserves to be shot), and the quality of care was very good with very attentive nurses and a consultant that didn't in any way seemed rushed when going through the results of the operation with us.
Considering I'm used to the Norwegian health care system where hardly anyone goes private more or less because it's not generally considered worthwhile due to the high standard of care in the public hospitals (not that people doesn't moan, but I don't take much notice all the while most people including those who can easily afford it rarely bothers with private alternatives), I've been pleasantly surprised by the NHS considering the bad attention they're frequently getting in the media.
I realise there are problems here and there, but considering the number of patients they're handling that is inevitable. It is rather symptomatic of the British press that they always seize on an opportunity for criticism - baseless or not - but only very rarely write anything positive.
I'll still consider privat health insurance, but only because it's so cheap (a couple of hundred pounds a year) and I can easily afford it, and apart from the obvious self interest I think the more those who can afford it go private the better - after all it frees up the public system for those who can't afford the alternatives.