Several posters seem against this proposal. But I have met parents who used to think like that, and as soon as it came to forcing their own children to go to a local 'less than good' school, guess what happened? Their views flipped as fast as a pancake.
There is absolutely nothing wrong with doing everything within your power to get your DC into a good school and I would say its your morale responsibility to do so. Its essentially an active protest against the state who are trying to force children into a sub-standard education.
Who's to say you are taking a place from someone who 'genuinely' deserves it? How many other family's have used money to live in the area? Its really the teachers, head, school, council or governments fault for not providing a good education to all children. It certainly isn't the parents.
As someone has already said this is no different than parents who use religion (genuinely or not) to abuse the system and get their children into good schools. That's a bigger scandal.
OFSTED reports are not currently a good guide to how schools are doing, unless its from this year. The inspection has just been changed to a more rigorous one, so you cant compare schools until they have all been redone. The previous system seemed to hand out good and outstanding ratings to schools that were only treading water.
I would rent out a few months before you fill in the application and stay until a few months after your DC starts the school. Don't tell the school your new address until the year after, they only ask for your it once a year anyway. Despite all the scare stories no one is going to pull your child out of a school they are already in, just because you decide to move house.