  We construct and discuss a "realistic" example of SUSY SU(5) GUT model, with
an additional U(1) flavour symmetry, that is not plagued by the need of large
fine tunings, like those associated with doublet-triplet splitting in the
minimal model, and that leads to an acceptable phenomenology. This includes
coupling unification with a value of alpha_s(m_Z) in much better agreement with
the data than in the minimal version, an acceptable hierarchical pattern for
fermion masses and mixing angles, also including neutrino masses and mixings,
and a proton decay rate compatible with present limits (but the discovery of
proton decay should be within reach of the next generation of experiments). In
the neutrino sector the preferred solution is one with nearly maximal mixing
both for atmospheric and solar neutrinos.
