With regard to the BZN MQ's we were unfortunate enough to live in one for 18 months. That was 40 odd years ago and I'm not surprised they have deteriorated, as they apparantly have.
Beagle is spot on re. Estate Agents and developers. There was lots of prime building land available around Carterton in the early '70s. Builders were buying out the smallholdings dotted around the place but, have got planning permission to build, they just sat tight and waited for the inevitable price rise that a housing shortage would bring. Gazumping was rife and Estate Agents were taking deposits on the strength of an 'artist impression' ie I put down £150 deposit on a house yet to be built, priced at £5100. Nine months later it was finally released for sale, though not yet built, at £11500! It was way beyond my means but I eventually managed to buy a modest semi for £7500. The next phase of identical houses, released 3 weeks later, were priced at £8500 and guys queued all night down in Witney hoping to buy one. On the strength of this situation I believe a law was passed requiring Builders to build within six months of obtaining planning permission.