I went thru this thread and decided to add my 2 cents.
Let me start by saying that we just got our first chickens in May.
We have 23 4-5 month old pullets and a 1 5 month old cockerel in an 8'x12'x7' tall covered open coop.
The floor is raised 2"x6" with about 1/4" gaps.
We live just outside Phoenix so we are very warm and dry for most of the year which is why we decided to go with deep litter.
I use a combination of cedar and pine shavings with some of the fine pine shavings. We also have a horse so once or twice a week, they get a flake of alfalfa to pick thru which they spread out far better than I could.
Scratch, the alfalfa, sunflower seeds, just about anything that goes into the coop generates activity which serves to stir up the litter.
We recently added a kiddie pool with about 4-5" of sand in it to give them options. They seem to love it as well. It will be at least another month before we start allowing them to free range during the day but so far even with running a misting system at times, the floor has remained dry and odor is nil.
The first time I turned the litter I was amazed at how much they compressed it. Before raking it appears to be no more than a couple inches deep. After fluffing it is closer to 12" deep. Within a day or so they have it packed back down tight. I add litter every 3-4 weeks to replace what gets kicked out of the edges of the coop and freshen it.
Septembers project is to add a 4'x8' enclosed roosting/nesting area for when the weather cools. No one is laying yet which we suspect is a combination of the intense summer heat and the age of the birds. We are actually hoping that with it being as hot as it has been, that they will not start for at least another month.