Shipped from India thousands of miles away,
equires lots of fresh water for cleaning
Coir is less acidic, and lasts longer
dispute about which one holds more water is pretty much irrelevant, since both hold so much water that as a soil amendment, both would dramatically boost soil water and nutrient retention.
Coir contains a great deal of lignin, which makes it very slow to decompose
Peat bogs are valuable wildlife habitat, valuable carbon sinks, valuable water filters, Renewable?
Peat moss may acidify your soil enough that some of the more sensitive plants may need the soil to be neutralized before they can thrive.
Peat bogs are a natural carbon sink that hold more carbon than all of the world's forests
Peat bogs are also habitats, which mining disturbs.
Large bales of peat moss are cheaper
Liming to balance acidity – (MY NOTE: not a concern for LA as our water is alkaline and the acidity of peat might prove more benefical in the long run... )
The Canadian Sphagnum Peat Moss Association's study supporting peat moss as superior: