A big thank you to everyone who has joined in on this thread. It's been great to discuss this.
We spent the day in Delémont yesterday. Still alarming how empty the highstreet is on Friday morning (more tumbleweed ..

) but were very impressed by the billingual class teacher. Seems it is exactly what eldest son will be after as it is to aid integration into the French speaking system whilst at the same time supporting their German so as to give them wider options later on.
What was striking was how welcoming and happy to help people in administration there were .. thinking particularly of the education department where they have gone out of their way to answer our questions and get hold of people who they think we would be interested to talk to. Of course the lack of language barrier is fantastic so if someone in the parks department could just expedite the building of a supa dupa town play park for the 3 year old, I think we're off ... or maybe we will just have to keep on coming into Basel for our urban playpark experiences (oh yes, like we do now!)
Thank you to everyone

and keep your Delémont thoughts coming in...