I don't really know about France (it's true that even under normal circumstances, anglo-saxon tourists prefer France to the French; but that's mainly because of the language barrier).
In Belgium, my father being a Rotarian, we used to host american students (well, we did once in 1971) and it's more an opportunity for us to learn english that it was for them to learn either french or dutch.
Some were very successful, others left mitigated remembrance. It's case by case.
But it must have been in general very constructive (for boys, it was nearly impossible as we had the draft coming towards us if we left for one year).
My brother met in the US a Belgian girl who at the time spent a year in the US as an exchange student and she surely enjoyed it.

Raoul