Loads and loads of families move down from London to Canterbury. Maybe a quarter to a third of all the day pupils at all the private preps have parents who relocated for the lifestyle. (And it is a good lifestyle; relaxed, healthy, lots of active kids learning to sail and surf in the summer, and lots of people in the same boat, so it is quite easy to use the parents network to link in with other 'newbies' and get good friendships going).
JKS does not really encourage children to sit 11+ and only around 6 children a year actually sit the test. Even the ones that pass don't normally leave the school. At JKS it is anticipated that virtually all children will go on to the senior school. And indeed this is what happens. A small number of children will go to other senior/secondary schools - maybe 2 or 3 a year out of 60+ - but they really are the exception. That isn't necessarily a bad thing. Senior school has a reasonable reputation, and because children get their offers for the senior school in yr 6, the children do not have the extra pressure of needing to get certain grades when it comes to sitting Common Entrance at the end of yr8.
School facilities are great, the teachers are fantastic, and I don't think people are worried about the change in head that's a very diplomatic statement. Things that may make you want to pause are the following:-
- A fair number of children have been moved from JKS to Kent College during their prep years, and those who have moved their kids are very positive about the experience (main reasons cited are cost/SEN support/holistic approach).
- I think that the top preps in and around London (I'm thinking Gordon's, Westminster Under and the like) are better at preparing their top flight kids for scholarships at the very best schools; AFAIK the JKS scholarship group is aimed only at the senior school itself, and does not follow the ISEB scholarship syllabus
- Saturday school is optional from yr 4 and compulsory from yr 5. Whether that is good or bad depends on your politics.
The grammar options in Canterbury are fantastic for boys (Langton Boys is 'super-selective' and does joint projects with NASA and CERN), and I think are OK for girls (the Faversham and Sandwich grammars seem to be more favoured by those with girls, although popularity goes up and down). If you are thinking of grammar for secondary then bear in mind that where you chose to buy a house could be important. And if a route to grammar is what you definitely want then St Christopher's prep school is aimed solely at 11+ success (95% success rate). That's NOT a recommendation for St C's by the way (just how it is - personally I'd not send a child to St C's).
Post already far too long so will leave with one bit of advice: Visit Kent College as well before making a decision. Very different school, very well regarded locally, nowhere near as prestigious, much wider academic spectrum. pros and cons, but worth seeing both before deciding (I say that as someone who is not a KC mum)