Expensive, heavy, particularly when it gets wet, needs to be double layer for waterproofing, single layer for windproofing. I think of it as a sort of natural soft shell. It feels reassuringly sort of retro though and is very quiet in use and pretty breathable.
It works, in waterproofing terms, by swelling up when the fibres get wet and soaked, hence the weight increase.
Personally I’d not bother – you also need to bear in mind that although cotton is a natural fabric, quite often the production process isn’t particularly ecologically friendly.
But all that aside, it has a certain esoteric charm of its own 🙂