Too much experience, is a bit of a bastard, sorry.
My Stafford partially tore his at 14 months (this was many years ago) at the time the prognosis for surgery was a bit iffy so I elected to treat with rest and anti-inflamatories when needed, he had good spells and bad spells for the rest of his life.
My friends Rottie completely tore hers at age 6, she had surgery, rest and god, whats swimming in water therapy called? That (sorry brain dead, up all night with poorly ds). Made brilliant recovery, still sound at 12.
Friends Stafford cross 13 months, partial tear in both legs, poor baby, have been trying to treat with rest and anti's for months and months, have given up and will be having surgery, looking at a year for recovery
.
Generally I think unless you have a very quiet dog and household and can pretty much crate rest your dog then resting does not work and it is better to push for surgery, otherwise you just set yourself up for months of ups and downs.
Arthrititis (not spelt right) is pretty much inevitable in old age.