Hi there,
Our son is at Wix Primary in the classic stream. He's in Reception and we've been very pleased with the school so far. He's happy there, has made many friends and his reading is fantastic (for a 5 year old!). As a mum, I really appreciate Wix as a friendly community, with very involved parents and an active PTA. I am French and we initially picked Wix with the bilingual stream in mind. We didn't get a place in the bilingual class but we have not regretted our choice.
If you want to compare the school to Honeywell and Belleville, in regards to your concerns, here are my thoughts.
Academic results:
As mmb posted, in 2013 Wix ranked between Honeywell and Belleville for its KS2 results. The teaching at Wix is good, and so are the results.
English as a first language:
Yes, the school is a great mix of nationalities and cultures, with a very strong French presence. It is something that I see as positive rather than being an issue, especially as it doesn't seem to impact the school's results. The school had an international food festival a few months ago, with parents bringing in their national dishes. It made for delicious tasting!
Children with special educational needs (assuming this is what you meant by behavioural difficulties):
Ofsted School Data Dashboards provide those kind of statistics. This is the link to the dashboard for Wix:
http://dashboard.ofsted.gov.uk/dash.php?urn=101025
The % of pupils supported by school action plus or with a statement of SEN is above the national average at Wix and similar to the one at Belleville. This level is much lower at Honeywell. Whether this is a positive or negative attribute of the school depends on your perception really. Wix seems to provide the right support to these children, and I think it is good for my son to be exposed to the reality of life diversity.
One point you didn't mention is the school's mix of social backgrounds. I suspect that when people say that the school is "on the up", they might be talking about the school's demographics (and the real estate prices rocketting in the catchment area) just as much as its results. The % of pupils eligible for Free School Meals at Wix is higher than the national average. This statistic is much lower at Belleville and lower still at Honeywell. I do not want my child to grow up in a bubble, so I am happy with this. I agree with mmb that the school will probably lose this social diversity in the years to come. There is already a big difference between KS1 and KS2.
Obviously, there's a lot more to a school than statistics and you should try and attend open days and school fairs to see if a school feels right for your child and yourself.
There is a lot to consider, good luck!
PS: I am no statistician, just a mum happy with her son's school. Please do not shoot me if I misread/misinterpreted any data!