The value of a qubit is, in effect, a complex number. To specify a complex number requires an infinite (and in fact uncountable) number of bits. So in terms of the information that's stored, a qubit is the equivalent of a large infinite number of bits. The extent to which you can make use
You cannot, of course, extract all of that information. As Peter Shor points out in comments, ---Holevo's Theroem says that is, the extent to which you can distinguish between the (probability distributions of) the results you get by observing two qubits with very close values --- is a question about engineering, not about physicsextract at most one bit.