Low Gravity vs Low Pressure sewer systems

[Watson]

Can any one tell me the difference between them, the advantages of one over the other? We have a community of about 1000 properties, with a mix of seasonal and permenant residences, and many permenant residences are snow biirds and not around in the winter months. Thus, with less people here in the winter, any flow will decline and freezing could be an issue. Would eith system be effected by slow flow and freezing?