As you would expect, Perahia plays beautifully in these recordings, but occasionally I miss the sense of drama and grandeur so essential in Beethoven. Perahia's approach works best in the 4th Concerto, which is given one of its best performances here. Warmly lyrical, with a beautiful interplay with the excellent Concertgebouw. The first movement especially is an unqualified success - I don't think I've ever heard it so poetically played. Maybe the second movement could be a bit more dramatic and the finale more energetic, but overall this is one of the finest recordings of the work I've heard.
Elsewhere, Perahia's playing, while always beautiful, is just a bit too plain for my tastes. The 2nd Concerto, for example, lacks the youthful energy that Kovacevich brings, or Brendel's humour. The 3rd Concerto is appropriately dark, but here again Kovacevich is more fiery in the outer movements and poetic in the slow movement. The only relative disappointment is the Emperor Concerto, which is a bit bland compared to the majesty, grandeur and energy other pianists bring, from Gilels in his splendid recording with Ludwig to Arrau and, of course, the young Kovacevich.
Ultimately, it depends what kind of Beethoven you prefer. For a Classical interpretation that emphasises the music's Haydnesque traits Perahia is your man. But if you want more energy and contrast, I'd point you towards the Kovacevich/Davis cycle.