Catchment areas will be stuck to fairly tightly as the baby boom kicks in, I suspect . This year I know 2 kids out of catchment for Parkside but who went to St Matthews for primary that got places. I also know 4 who live close to Coleridge and went to other primaries who also got places.
In 2016 4 people from our locality (Romsey) went to Trumpington. One of them switched last minute after disliking Coleridge on transitions day visit in July. This year several parents at our primary placed Trumpington top of the 3 and none of them were offered a place for their child.
I think being in catchment will be of greatest importance as the baby boom kicks into the equation. So if there are children who live out of catchment but attend St Mathews they will probably be less likely to be offered a place this year.
So, how good are certain schools or how good are they perceived as being?? Coleridge still has an image problem as does North Cambridge Academy. Netherhall seems on the up in the popularity stakes as far as parents in Romsey as concerned. But, as was said earlier, central Cambridge doesn't really have any schools that are really so problematic.
I may be a case in point myself. As I reached secondary age, grammar schools went out and we found ourselves with the choice of Manor (North Cambridge Academy site) or Chesterton. Way back then one only contemplated Chesterton if ones parents went there. Times change, reviews and Ofsteds change and throughout this schools deliver to kids who want to learn. By the time I went to 6th Form College on the premises where I might previously have received a grammar school education, there were just as many kids from Manor as Chesterton.
Basically, just try to chill about it and check out the local school where ever local turns out to be.