Peat moss vs. coconut coir is an ongoing discussion in the gardening world. There is a great discussion following the article in the comments: Garden Rant: Jeff Ball Defends Peat Moss.
I haven’t been using the bag of peat moss that I have in the shed because I was informed that it is a non-renewable product and coconut coir is renewable. After reading the article and discussion I am still not sure what to think. Both sides make good points. I do know that this summer when my compost was way too wet with maggots in it I added peat moss because I desperately needed carbons. And that took care of the problem. It balanced out what was happening in the compost tumbler, the maggots died and I soon had a very nice compost. This year I hope to avoid the problem of not enough carbons because I have been saving leaves and collecting bags of raked leaves to store for the summer.
Another article on peat moss just came to my attention. It is by Ken Druse and is very much against the use of peat moss because it is not a sustainable product: The Real Dirt on Peat Moss He offers superior alternatives including shredded leaves, compost and coconut coir.