Thanks both @QuiteAJourney and @MomFromSE for so much common sense here. Agree with so much of what you're both saying.
Of course there are children who are naturally competitive and thrive on competition (you only have to watch 10 or 11 year olds doing elite sport to know that).
But one of the sad truisms about the 11+ arms race is that sometimes it's the parents' sense of competition that's driving the process, not the needs or the best interests of the child. I've seen it year-on-year at my DD's prep: parents being categorically told that, for instance, SPGS isn't a good fit for their daughter, the parents refusing to believe it, tutoring their child to the hilt to earn a place, sometimes being successful (and who knows how that child will then fare) but more often not.
On the list of criteria as to what should be factors to consider for the next seven years of a young person's life, hopefully for most (sensible) parents, "How I'll feel telling my friends that my child goes to X school" won't even factor. Schools are not a status symbol for parents' reflected glory. (Though sometimes in SW London you might be forgiven for thinking that's the case!)
And totally agree @MomFromSE (and have made this point many times on iterations of this thread) that in terms of pure academics and a child's outcomes, it's a case of splitting hairs as regards the schools everyone's discussing here. The same child is not going to drop 20 UCAS points because they go to Emanuel rather than LU or PHS rather than G&L.