Great question. There's no way to know outside of big randomized trials but I'd bet thousands of dollars it's the latter. (edit: surely this
has been studied, right?)
Though, I'm certain it would be less "perceiving excellence" like a connoisseur, and more like reaping the practical benefits of solid typography.
While there's certainly a lot of showy typography in the world, the sort found in the body copy of books is generally focused on readability, in other words, letting the eye/brain more easily recognize letters and words. Do we enjoy a book more when our eyes and brains aren't overtaxed? It's hard to imagine otherwise -- who enjoys eye strain?
I'm less sure of it but I suspect this is true for lossy vs. lossless music as well. For example, one telltale sign of badly compressed music is when the percussion sounds more like blasts of white noise than the actual instruments -- these sharp transients are hard to losslessly compress efficiently. (It's somewhat similar to how the sharp edges of text and line art are not handled well by some lossy image formats like JPEG)
Is a drum that actually sounds like a drum going to be more pleasing to the ear than something garbled and white-noisy, even if nobody tells you anything? Generally yes, I am fairly sure.