Post, Homogenic and Vespertine I consider personally as their best albums. Medúlla was too much "a cappella", Volta was treason and Biophilia was too very Apple-related ;-)
But the new album is directly linked to its high-time and provides the right mix of the above mixture of styles without too much rumzuexperimentieren. Somehow reminds me the "Instrumentation", if I may call it so as Musiklaie, quite to the unforgettable concert with the Brodsky Quartet.
Clear, Björk polarized ... but who does not scare you, the expected a good album that clearly belongs to its better.