We picked SPJ over WUS. Despite WUS's reputation, the open day experience was tbh underwelming and even though the pupils and staff were perfectly lovely, it was a little disorganised, and then of course the facilities do not compare to SPJ.
Our overall impression remains that the academic output is WUS's primary focus (hence no automatic transfer to the Great School and intake of top girls at 16+ to boost uni results). Extracurricular opportunuties such as music, sports and etc, although offered, is perhaps lower priority in the boys' overall development. If you compare GSCE results from the orginal cohorts before 16+, there is nothing really to seperate the two, which sways us even more to SPJ where the pressure seemingly is less, i.e no Sat school.
Current WUS parents may beg to differ, but that's just our opinion after the whole 7+ interactions with both schools, so please do not feel offended. KCS feels more well-rounded but we declined due to distance.
Also just to add that this year's SPJ 7+ assessments felt the most academically intense of all 3 top boy schools. My DS found SPJ the hardest and he really enjoyed the 2 rounds at WUS and came out bouncing.
Ultimately you can't go wrong with either of the top 3 and we went with SPJ as it suits us best as a family. Time will tell.