[Nicolai P. Zwar]

What’s your take on bonus material like this in boxed sets?

I think they are what the title says “bonus” material. Not essential, not belonging the the “main presentation”. Hence I usually don’t listen to them in context of the “main program”, but “separately”, depending on what they are. “Bonus” tracks can obviously be all kinds of stuff: alternate takes, alternate cues, alternate edits, demos, sound effects, dialog, interviews, source cues, jingles, whatever…
“Bonus tracks” are for those who want to explore something in more depth, get a bit down to the “nuts and bolts”, perhaps learn something about the process. They are like alternate or deleted scenes from movies. (I always thought the alternate ending sequence on the SE7EN Blurays very interesting, however I am very glad they went with the ending the movie now has.) Interesting to see and learn something about the score, but not “essential”.

So I sometimes listen to them, but often at a much later point, often when I’m more familiar with the main work. Some “bonus tracks” I actually put to use: for example, sound effects libraries can be quite nice. I have outfittet my smart phone with some sound effects of Star Trek sounds from the STAR TREK GENERATIONS movie, so when I get a PN on Whatsapp, it’s the communicator sound from STAR TREK.
Some are just interesting, like Craig Huxley performing Blaster Beam solos (to demonstrate the instrument) on the La-La Land 3CD presentation of STAR TREK – THE MOTION PICTURE.
But whether they are on a regular CD or in a Box Set… they are “bonus”, like something “on top”… added goodies, for Academic interest or just plain fun, that you can do with as you please or ignore.
I have a Debussy La Mer recording with a bonus CD where Pierre Boulez talks about his relationship with and approach to the music of Debussy, Webern, and Mahler, which I love, because it gave some real insight.