I'm not sure about Wilsons but if as the others say they are equally good schools I would opt for the one closest to you or the school located in the area you would like to move to. My son is at St Olaves and although it is a very good school it is not without it's issues. The new headmaster Aydin onac is widely disliked in the school both by staff and students causing a mass exodus of teachers at the end of every year which I feel hinders DS study. Just as you get familiar and comfortable with a teacher he/she leaves. Standards for entry to sixth form have also been raised so if you don't cut the mustard at GCSE you will have to leave. The pressure is immense. Google the headmaster for more info especially on rate my teacher, it makes for interesting reading. We based our decision to send our DS to St Olaves when the previous head Anthony Jarvis was at the school, things have certainly changed now.
I have read the comments about Mr. Onac on rate my teacher. Comparing comments made about him with my dd primary school in South London and Rochester Grammar School in Medway, it is very clear that he has a very high academic and behavioural expectations from both the pupils and teachers. I think our children need a person likes him and the school system also need people like him and that is why Ofsted has a new head in January. The new Ofsted chairman or head used to employ former soldiers to work in his school. He succeeded in transforming the school as behaviour improved and they started getting good results as well. Michael Gove gave him the ofsted job as result of this.