Karajan's best period for Beethoven, which makes it among the best periods in the second half of the twentieth century, came in the Sixties. These eleven overtures were recorded in two sessions in 1965 and 1969, showing all the power and integrity of the conductor's mature Beethoven style without the glossiness that would soon creep in. All the performances are of a piece, given large-scaled readings that tend to merge the earliest overture (Creatures of Prometheius 1801) with the latest (Consecration of the House 1822). All of full of energy and commitment, and the measure of their success is that in the succeeding forty years, no one has made a better collection. IN fact, few later conductors have bettered any of these readings, unless you can accept the turn to HIP Beethoven that makes his music sound like bastardized Haydn rather than the revolutionary turn to Romanticism that it actually represents.
I think the three-star reviewer is entirely off base about the sound, which isn't remotely treble-laden on my system; if anything, the recordings are a bit distant, boomy, and dull on top. But that's a quibble; this is good analogue sound for the era. I can agree, however, that Karajan cannot be compared to Furtwangler, but then, they come form very different musical - and philosophical - worlds as far as Beethoven is concerned. Karajan doesn't reach for the utmost tragedy, triumph, or moral authority, as Furtwangler so memorably did. Without acceding to Toscanini's tight, disciplined style, Karajan certainly took it in mind. There's a great consecration of the House Over. From Klemperer in full Romantic style, but Karajan's fast, thrilling one is great, too.
On the used market this set is a great bargain. Strangely, there aren't many collections of Beethoven overtures, and none that are this complete. I wouldn't be without the Klemperer on EMI, although it omits a few (no one needs to bother with Namensfeier more than once, a work so generic that Beethoven published it as suitable for any grand occasion). There is a Szell collection that is basically Toscanini in better sound, a stodgy Colin Davis, a pedestrian Masur, and, coming closer to a true rival, and early Abbado, now out of print, that covers all of this music with the Vienna Phil. in less exuberant readings that represent probably the young Abbado's best Beethoven.