Which stone should one take?

Sorry nameless one, but the sentence about Ytong: "Those are the houses where I can break in with a chainsaw. Simply no compressive strength and hardly any sound insulation." is probably completely made up and really, as Bauhexe says, stupid nonsense. I live in one of those, and can say that the sound insulation is excellent, we hear nothing inside, neither cars nor lawnmowers or anything else...