DD didn't have it. She had a bad reaction to the first one. The first one is supposed to be 90-95% effective I believe, so it depends whether your child is immune or not. You can be tested for immunity.
DD1 hasn't had it. She was diagnosed with cancer at the time her MMR booster was due, so all immunisations have been put on hold. We have to rely on everyone else getting their healthy children vaccinated.
Daughter is OK now, she's 11. I've not had her tested to see if she is immune. As for being chased - we kept getting chased, they kept sending us appointments, and I kept cancelling them. In the end, when we moved house, I didn't cancel that last appointment - and do you know what? They marked her down as having had the MMR at that last appointment (when we were on holiday in a foreign country!)
Interestingly enough, DS didn't react to either of the MMRs, and he has Asperger Syndrome!
It depends on the reaction. My daughter was like a zombie for 3 days. Stopped talking, stopped running around - it was the scariest thing I have ever seen. Can you imagine putting a normally lively 2 year old child down and watching her just stand there, not moving, until eventually a silent tear just trickles down her cheek? And then, on the 4th day, she just snapped out of it. I decided a 90-95% chance of being fully immunised was enough. And like I said, even after that, I still had DS immunised...
Our DD also didn't have the booster at the required age either, instead we had an immunity test done and she turned out to be highly immune to all three. As far as I know testing can only be done privately. We had our done in Dr Halvorsen's BabyJabs clinic: http://www.babyjabs.co.uk/antibody_tests.htm
No - one dose is enough in my humble opinion. GPs still bring it up every time I am there (Youngest is now 5!). If they were so concerned surely they would have funded a basic immunity test (request was flatly refused by them).