I'm certainly not averse to box-sets, but these are a bit much for me. I looked at the Schubert set, and the Hungarian Quartet and Christian Zacharias aside, I'm not too interested in the recordings. Given EMI's "The Greatest Artists" line, you'd figure they pack the set with their best stuff, yet where's Beecham's timeless symphony recordings for instance?
The Beethoven set is much better: Eric Heidsieck, Ferras / Barbizet (which I'm listening to right now as it happens), the Hungarian Quartet. Yes, this may be worth a few bucks.