If you are a Mozart freak and just have to own all that genius's music, this is the least expensive way to start (though it is not an exhaustive collection). In general, it is a very good collection, performed by a wide variety of orchestras and singers. However, the quality on some of the CD's is noticably poorer than one might hope - lacking the clear, crisp sound you might expect on a $25 CD. But for this price ($132) for 170 CDs, it is still well worth the money.
I only wish they had recorded them chronologically so the listener could appreciate the development of Mozart's genius. Instead, they lump symphonies together and concertos together, etc. Not nearly as much fun.
I own both this set and also the Bach Edition set. Although there are more discs in the Mozart set the box is about 2/3 of the length of the Bach Set. The sleeves in the mozart set are more a spectrum of color so that from a distance it looks like a rainbow. This looks nice but makes it slightly more difficult to find the disc you want then the Bach edition. The discs have nice color labels while in the Bach set they just have black words. The envelopes are thin paper rather than the cardboard used in the Bach edition.
So I think the Bach edition has better packaging, but this set has more music in it and fits in a smaller space. Great music. I really enjoy listening to it. It is nice to listen to uncompressed music and to have to swap discs instead of changing songs with a flick of the mouse.
Most performances and recordings are very nice, e.g. the sacred music and some of the Divertimenti. The symphonies are played quite clinically, but Jaap ter Linden permits the polyphony to come together beautifully, and the recordings are superb. Some of the piano concerti need a lot of added 'lightness', it seems like the performers are at the edge of their capacity to play these works. I believe Mozart's music to be among the most difficult to perform well. Some recordings are poor to mediocre. Pricing on this set seems to be as inconsistent as the quality of the discs, weird. I would estimate that about well over 100 of the disks are enjoyable to my ears and taste. Still a great deal at the price I paid. There are some big name performers on this set that I used to associate with Baroque music on period instruments.