Erasmian vs. Modern pronunciation?

Any discussion of the relative merits of using ancient or modern pronunciations of Greek should acknowledge that, at least in English-speaking countries, the widely used pronunciations of φ θ χ are purely conventional and not based on ancient phonology. English speakers aspirate p t k where ancients and modern Greek speakers do not.

Likewise vowels are generally conventional, compare the ending in φίλους pronounced in Slovenia as ŭ, in the USA as ū.

ου was originally a long o higher than omega (aw), raised, became long u when upsilon in Attic moved forward to become an u like French u long and short.