As far as I have experienced, the "classical" (i.e. not the Italian-like ecclesiastical) pronunciation differs a lot by native language of the speaker. It was long ago, but I remember having had only very basic pronunciation guidance at my secondary school; we certainly used Dutch vowels (apart from the "u" of course) and the Dutch "v" which is very similar to the English "v". In a context like that academy I would have been understood, but with a very typical Dutch accent.