I've got two hats on when replying to this thread.
The first is as a mother. We have always taken our DD out of school for term-time holidays - primarily because up until this year my DH's job has not allowed holidays any other time than October or May (luckily that's fitted in in with our wish list for holiday times). Also, financially, it has been cheaper to go at these times. However, I have noticed the prices creeping up in October

The travel companies have definitely cottoned on to how popular it is to go away with children at this time of the year.
Each tme we have taken Katie out of school, before booking I have asked her teacher if it would be ok. We are lucky to be blessed with an "able" child, therefore her schooling has never been an issue and each time her teachers have been more than happy for her to have time off, especially since we've been lucky enough to visit places like St Lucia, Hong Kong and the Philippines, as well as Florida. All vastly different cultures to our own and Katie has done a journal of her trips each time. Geography "mini projects" have varied from the Mountains in St Lucia, to tall buildings in Hong Kong, poverty in the Philippines, to The Everglades in Florida - all useful things to learn about.
BUT, she is now in Year 7 in senior school and I have always said - and stand by - that I will not take her out during term time for long periods of time. The work/homework is very different and a lot more of it than primary school and I wouldn't want her to miss out on any "just" for a holiday - this is because she's normally missed two weeks of school for our three week holidays, the full "10 days allowable authorised absence".
Mind you, we're off to Florida this August and OMG the price is frightening

But we know this is going to be the last trip to Florida for a few years since there's loads of other places we so want to visit, so this year it will be and the only time we can go for three weeks is during the Summer holidays.
Secondly, I am an Admin Officer at a school. Therefore no term-time holidays any more for me. A real bummer, but when I weigh up the pros of all the school holidays I DO get off, it doesn't seem so bad (until I look at the invoice for the cost of the trip this August

).
And this is where it gets emotive, as Karen says. I am astounded by some parents attitudes when it comes to asking permission to take their children out of school. And permission IS required by the local education authority.
I do not have a problem at all for people taking children on holidays for both financial and family time reasons. However, some of the excuses we get are pitiful and this is why both the government and local education authorities are trying to crack down.
I'm only going to give one example of a child who had a day off last week. Got a call at 11.30 in the morning to say little Treasure wasn't going to be coming into school today since mum and dad were taking her to buy a puppy. She then had two more days off because she couldn't bear to leave the puppy on its own during the day

This is a Year 6 student, coming up to SATS in May and with a heavy revision schedule because she doesn't cope so well as other students. Sorry, but totally irresponsible and the teacher is already feeling stressed about how to get children like this through exams which are important not only to the school, but more so for the child's future.