It made me smile that you feel that everyone chooses Southend, as my experience is the reverse!
I only know a couple of children taking the 11+ this time, but when my elder son took it, I knew slightly more, and from this area hardly anyone even visits SHSB let alone puts it on the form. It's all KEGS and WHSB here.
I don't know if you read my original ramble but part of my concern was how much of a local school Southend is! Isn't it funny how you see it as a rebellious choice to put WHSB first, and I felt the same about SHSB a few years ago!
(I do agree with you about Open Days, btw, but this wasn't true a few years back, Westcliff have really upped their game in this department, really impressive!)