Hi
I worked with at KS - the junior side not the infant side but here it si a fantastic school - we didn't look because it was out of our catchment (hence why G is going to independent school).
However, there is a girl Kelly Pattison (i think she got married a few weeks ago so may have a different surname) - anyway i worked with her for two years in the school i taught in - I was year 3 teacher and she was a year 1 & 2 teacher. She is absolutely fantastic and raves about the school - they draw from the less wealthy areas of SW so have trouble being considered as good as RAB or the other schools - however, you know my opinion on OFSTED and league tables and to be honest KS is a very good school.
I think you need to ask - what their gifted and talented policy is, what their behaviour poilcy is, marking policy - lots of schools rave about their sticker systems, Golden time (children can choose what fun activity they do on a Friday) but it very rarely exists to the extent they say it does - ask to look at a sample of books - you can see teacher's comments and see if the school really does follow through with positive marking, free time, how they reward children, staff turnover rates, support in the classroom, do teachers get to take their breaks and if so who covers your child's class in this time, do they have an open door policy, whose work is on the walls - i think this is very important - i have been to see a lot of schools (i specialised in special needs - both ends of the spectrum) and have seen lots of display boards - i have seen beautiful ones which if you look closer are made up entirely of the Learning support assistant and teacher's work with the odd child's contribution. However, the best schools always have the childrne's work and a selection of 'good and bad' examples - you cannot compare two children so although some work may appear a little scruffy, untidy or not finished - are you judging by what your capable of or what the child is capable of - all children love to ahve their work on display and i believe that if schools value thier pupils then they will endeavour to display all types.
Make sure it is not too quiet - children do not learn through sitting down and doing a worksheet, they learn through talking, acting, playing etc.
I know i have rattled on but please DO NOT be fooled by what you see - remember that the school and all the staff know you are coming, your name will be on the white board in the staff room, the staff will have been briefed about the time you are coming, the school will also have dictated what times you are permitted to come and look.
Hope this helps