I like a horse’s stall to be fluffy and volumous for their comfort. A cushiony bed of shavings over even mats is far more comfortable than 3" of relatively compacted sawdust.
That said, I don’t use big shavings because my horses aren’t in their stalls for more than a couple hours max, usually not even that long, and the very occasional overnight stay during awful weather. I used to use it, for a year or 2, but man it’s a pita to pull clean but dragged around hay out of, you can’t separate manure very well from it, etc.
Having used it for years, whether where I boarded at a co-op (so cleaned my own stall), or the first year or so at home, and having used pelleted shavings for the last 12-ish years, I can say the smaller particle bedding definitely lasts longer. A lot longer.
I let the amount of bedding diminish naturally as stalls get cleaned of the occasional manure pile and urine spots, and when it comes time for an overnight stay, I put a few (3-4 depending how depleted the stall is) bags of new pellets (the kind that doesn’t have to be wet down) under the existing bedding, so they have more volume for the night. Pee spots then tend to be really easy and “clean” to pull out, and the pellets start mixing in with the broken down bedding, and being broken down themselves, and then it all is in there until, usually, the next year when I start the cycle again with new bags.
