Let's talk about the orchestra of period instruments create a whole new balance between the desks. The wood has a more subdued, less aggressive; the strings have a finer sound, a little more acid; brass, further back, do not obscure other voices. All this illuminates the symphonies in a different light, and demonstrates how Beethoven was operating all facets of his orchestra. For example, the beginning of the Fifth is less "solid" less solemn than the contemporary orchestras, but not so dark! But it is the Sixth that surprised me the most, more peaceful, more authentic ...
But what would the orchestra without Gardiner? It coincide with these new sounds very fair reading of the work, with dynamic and well controlled tempi, and that illuminates Beethoven's revolutionary writing, his budding romance, its classical influences and accents brahmésiens.
In summary, much more than full: a reference. To afford urgently!