Thanks happy for outlining what you liked about your dc's top prep. Interesting that you put such a lot of weight on having specialist teachers for different subjects. I can see that the prep model might be attractive if you think that's important. I guess what you describe is a very traditional approach to education, which is fair enough if you want that kind of thing, but it's not what I would look for.
Personally, at primary level, I put much more weight on teaching skills than specialist knowledge in a particular subject area, and also on the children having the opportunity to build up a strong relationship with one particular teacher who gets to know the children really well as individuals - separate teachers for every subject was one of the things I specifically didn't like about our nearest prep, because I think that overview is lost.
Also, I loved the interdisciplinary nature of the curriculum at dd's primary school, and the clever way in which the different subjects are woven together around a common theme - this is something that dd's school is especially good at, and it's a constant source of amazement to me to see how effectively they do this. I think it's really exciting for kids to find connections between subjects and I think dd learns much better in this way. The school does have specialist teachers for some subjects - art, PE, French and music - but I don't think it's necessary at primary level, and for me, the cross-curricular thing is much more important, if it's done well.
The children are still exposed to specialists in various curriculum areas where appropriate. For example, the local university does a science day for the school once a term (for KS2), and at other times during the year, the brighter kids get to go and do stuff in the university labs, which is a big adventure for them. I think the partnership with the local university is hugely valuable, and at least half of the parents happen to work at the university, there is a very high level of interaction in various different fields.
They also have a range of interesting visitors coming in to the school from different professional backgrounds - for example, this year dd's class has had a professional illustrator who came in to do a masterclass and to help the children illustrate some stories that they had written. One of the archaeologists involved in finding the remains of Richard III came in to talk about his work, and as they are currently focussing on persuasive writing, they've recently had someone in who writes advertising copy to work with the children on that. I really like this balance of "expert" input from time to time, alongside the consistency of the relationship with the main class teacher, and this would be my preference at primary level.
I will concede that DD hasn't had the opportunity to learn Latin, but she did have the opportunity to learn Mandarin (from a qualified native speaking teacher) in a free after school club for 2x1.5 hours a week, and while I know lots of people emphasise Latin, I think that' modern foreign languages are more useful in this day and age. DD did do Mandarin for a while and learnt quite a bit, but eventually she had to quit because she wanted to prioritise her time for more dance. The French that they do in school is less satisfactory if I'm entirely honest - the teacher is very good, but they only do a couple of sessions a week so their learning is limited. However, as dd is trilingual anyway, I'm less concerned about this.
Extra-curricular activities are rich and varied. I've already mentioned the Mandarin classes. Then dd had the opportunity this year to work with a former west end choreographer who put together a dance festival for local schools. Obviously she does lots of dancing outside of school anyway, but it was good for others to have this opportunity. The school choir competes at various events and recently made a recording at a professional studio as part of an international recording project. There are loads of sporting opportunities at various different levels, including lots of competitive sport with other schools, but I know less about this as dd is only involved in the after school recreational sports clubs. My neighbour's child is very sporty, however, and competes in gymnastics at a national level. She does most of her training outside of school now, but she started off in an after school club.
PE is only twice a week at dd's school, but as I've already said, there are lots of lunchtime and after school clubs, and most kids participate in at least some of these - even quite unsporty kids like my dd does a couple, so I reckon the sports teacher must have some kind of magic about him! Games every afternoon sounds like rather a waste of time to me if I'm honest, especially 2.5 hours of cricket three times a week! 
Fine if that's an extra-curricular activity, but dd does so much physical activity outside of school with her dancing that I'd prefer the time in school to be spent on other things.
DD has had many other opportunities this year too - watching an RSC production of a Shakespeare play and talking to the actors afterwards, climbing and canoeing on a residential trip, learning about schools in other countries by communicating with partner schools overseas, participating in a really interesting inter school maths project for so called "gifted and talented" children where they've had the opportunity to apply their maths skills to real-life problems. There are too many examples to list here.
For me, a broad education at primary age is about not really about having lots of separate subjects taught by people who have specialised in those particular areas, but rather learning about a broad range of things from a broad range of people and starting to make connections between them. The kind of education that you describe sounds quite similar to what I saw when I went to our local private prep (though I'm not convinced that that's a "top" one) and that is definitely not what I would choose for my dd. But I appreciate that you might not want what I have chosen either. I guess we all have different values and priorities.
The one thing I will concede is that the facilities do tend to be better in private schools, obviously because the funds allow it. Our school doesn't do too badly, as we have a very active PTA and a generous group of parents; we also have access to facilities at the university such as science labs, auditoriums and an Olympic sized swimming pool! However, the school itself doesn't have the facilities that I would expect at a private school. I guess it's for individual parents to decide how important that is.