We have a 10 year old DD at Honeywell and a 5 year old DS at Thomas's Clapham. We moved to Wandsworth when my DD was in Y2, from abroad, and Honeywell was the best option available.
For our youngest, we had been in the area for longer and had more options available...
Would i wish my DD was at Thomas's too? Yes!...but such were our circumstances and also, i would still chose Honeywell over quite a few other local pre-preps (i know, it's a very personal choice).
-like noted by others, the financial commitment of going private is substantial!
- For going private at 11+, pretty much everyone tutors (from state or private schools). Maybe children from private schools need less tutoring, i don't know...
- if going private at 11, i don't think Honeywell is worse than local pre-preps in terms of results
- the big difference, in my opinion, is the wealth of extracurricular opportunities you get at a good pre-prep: sport, drama, music, etc ... if your child has a particular talent, she/he will be able to take it much further in a private school (facilities are better, more specialised teachers, etc). I don't think this necessarily means better 11+ results, just a more rounded education and better opportunities to find something they excel in. Yes, you could try to DIY this yourself with after school clubs, but it is much harder (and even harder if both parents work full time)... if you are streets ahead in violin, for example, that will give you a lot of confidence when you are in senior school, so maybe the 11+ is not the only end game ..
- Honeywell is great and it keeps the children very happy; and the diversity is great!; but staying in the same class all the way through is not great; the feedback from teachers will never be as detailed as at a good pre-prep (where they simply have more time to observe and discuss each child's progress); and I find that in some topics (like art, drama) the kids are not stretched enough; also be aware that in the later years, some children leave to go private
- from my (limited) experience, moving to pre-prep at 8 is not easy, as it relies on another child leaving the preprep (and the trend seems to be that less people are moving to the countryside); in my opinion, this would really be the best option, as all those great preprep facilities and opportunities are rather wasted on the very young children ... but unfortunately that's not how the private school system works, and (at least locally) there isn't a preprep with an 8+ entry point
Best of luck!