Depends where it comes from, alot of the crushed "concrete" round my way is s**t with a high soil content plus all the usual plastic, wood, metal, pieces of asbestos and what ever other crap bellends have tipped in the crushing pile. Also tends to have pieces to large for a Wacker so ideally needs a roller, then when it gets wet looks like mud.
Can also get a recycled type one round my way that comes out of a wash plant which tends to be 10-40mm mixed with "sharp sand" off another belt, all depends how it's mixed together but one issue is the moisture content from being washed so can bring water to the surface when Wacker although to be fair goes off solid when dries out.
Personally not enough of a saving for the hassle and haven't used any for a few years
Although do have 40t of crushed to use for a parking bay in a field next week so will see what sort of quality that is