Brand matters sometimes I think because some are more soluble than others thus easily absorbed by the body. But you may also not notice any change if your body was not lacking the particular vitamin of which you're trying to up your intake. In other words, if your diet was already providing sufficient biotin, then your body will just get rid of the excess you're taking and so you will not notice any change. After all, biotin is found in liver, egg yolk, green vegetables, almonds, walnuts, milk, cereals...to name a few.
However, if you were seeing a marked change with one brand, and not with another, then one is probably of a better quality than another.