I don't have an opinion as I haven't tried it. But from what I've read, coir is not the better option. I think there is some discussion on the container forum, if you try a search there.

I use composted leaves and vegetable scraps over either of the above 2 and get great results.

They can be used interchangeably. Both have different benefits they bring to the mix but both will function very similarly. Whereas highly decomposable materials like composted leaves and vegetable scraps can create drainage and porosity issues and increase the perched water table and will be needed to be changed out far more frequently. That is just a fact of life (and soil physics) with any container media.

Take your choice between coir or peat moss, Both work very well. I have used them both with excellent results. Peat has a lower pH. Coir is a sustainable product.

I personally use coco fiber and recommend it to all my customers. I find it holds it's structure better than peat so it doesn't end up clogging your pot and turning it into a sink. Just my personal opinion but I hope that it helps :)