I use it in my two big sheds - and it works very well as long as you have very good ventilation so that the litter stays dry. As to whether it could be called a true deep litter system I'm not sure.
My bedding goes down in October, and is then kept turned over by the birds and me, with fresh litter being put on top. There is no smell, the litter is dry (if it starts to get damp, usually because of rain blowing in through the mesh door - I just add more dry litter) and I clean it out come April. If there are big bits of damp litter under the perches, (I don't use boards under the perches) I just lift it out and dump in the compost bin. I also sprinkle Stalosan F on the floor when I first put the bedding in, and every so often a light sprinkling when forking over, to keep it all sweet.
The birds come through winter looking good, and because they are quite large sheds, it keeps them a lot warmer too. The upside is that the litter that comes out of there is usually well broken down and almost ready to go on the garden. The downside is that the little looks quite dark and dirty, so it doesn't reflect light like new litter does.
The bedding I use is Rapport. There is also a small amount of straw in there, as I do sometimes put some in to give the girls an incentive to scratch around in the litter and keep it open. It breaks down into quite small pieces and while straw is known for red mite and being damp, it is in such small quantities in comparison to the rest of the litter, that I have not had a problem.
I've been using the system over winter for the last three or four years. My smaller coops operate on a similar system, but are cleaned out every five or six weeks.