The clustering of quarks into pairs (diquarks) has been suggested recently to play an important role in dense matter and its astrophysical realization in neutron-star cores. We address in this work the features of diquark matter by employing an accurate equation of state valid for the effective {lambda}{phi}{sup 4} diquark theory, and find milder (although non-negligible) effects than in previous calculations. Some considerations on the very presence of a diquark-dominated region immediately above the deconfinement density are also given.