I'm not sure I would judge a school on the strength of one year's SATs results (whatever you think of Sats anyway). But then I'm a Dalmain parent, so maybe that's why I'd say that. I'm also not wild about league tables (my mum was a primary teacher until very recently and I'm well aware of the many, many factors that can affect results - as well as some of the factors that affected Dalmain specifically last year).
You could also look at Ofsted reports (though not all very up to date), and go round the schools (all very open to visits). I did all of that before my daughter started Reception, which is where she is now. It was very illuminating.
I've many friends who are very happy with Kilmorie and the new head. I'd also say that Dalmain is an absolutely fantastic school and our daughter is thriving - the size of the playground has not been an issue so far and the school also has the Pen and the Wildlife Garden, which help to extend its space.