I admit it, albeit shamefacedly, that I am a collector. From childhood, I have been fascinated by things that come in a series and are numbered. In my tender years I collected the nature books of Thorton W Burgess, each with their little starred numbers on the spines lined up in order on my shelves. Later, The Hardy Boys. In my adult years, any number of different authors' complete works (though, without the starred and numbered spines, alas). I was a publisher's dream.
Is it any wonder that, once I started into classical music I would become fascinated with Opus numbers and uniform series of records and boxed sets?
So, even though I try to force myself to be selective and pick only performances I love, when something like the Brilliant Complete Brahms, or Haydn Symphonies, or Complete Mozart comes along, I can't resist it. The performances may range from merely serviceable to good (and only rarely great), but it doesn't matter...it's complete!
I can't tell you how much time it took to spreadsheet the Brahms lieder on the Brilliant set to be sure they were all there, split up and mixed up as they are on ten or so different discs! Don't they know what it means to be obsessive/compulsive? Now, I'm going to have to copy and sequence them on my own home-made CDs.