Anybody have any experience or know anything about this group?
Their official name is "Opus Christi Salvatoris Mundi" (Latin for "The Work of Christ, Savior of the World"); however, their official name in English is "Missionary Servants of the Poor of the Third World", and in Spanish, "Misioneros Siervos de los Pobres del Tercer Mundo".
I read some literature about them that seemed impressive. Father Giovanni Salerno is evidently a humble and holy priest who has dedicated his life to helping the poor in the Andean Mountains in Peru. According to the account I read, he has worked miracles, including healings and multiplication of food, through the intercession of our Lady.