oohhh... how to answer without revealing my secret identity...!
I know really really good things about St Catherine's which is in Stratton so the right side of Swindon for Dorcan. It's RC though, so I don't know whether that would suit.
St Francis in Taw Hill has a good rep, as do several of the North Swindon primaries, e.g. Catherine Wayte, Bridlewood, Red Oaks etc. but it can be a bit of a lottery which one of those you get as there's so many families moving into that area.
Think long and hard before moving into the catchment for any schools that feed into Swindon Academy as it's got a very dubious reputation and there's a strong chance that other primary schools might get swallowed up into the Academy themselves.
There'll be them as tell you that you shouldn't go anywhere other than Super Duper Lethbridge School with all the Boden yummy mummies and their children Tristan and Tabitha. Don't listen to them (unless you're a Boden ym yourself and your children do happen to be called Tristan and Tabitha).
But it's like anywhere really - a good head will make or break a school and different children (even siblings) respond well to different types of teachers.
Great place to live though. Welcome.