Good question. Yes, I do tend to appreciate the more challenging albums over time, and usually I listen to them more once they've sunk in.

A good example is Soft Machine's "Teeth." I love the band, but this album gathered dust after my first couple of listens. Somehow, I came back to the record and began to realize what a wonderful combination of improvisation and discipline it represents. To my surprise, the song has a number of fans in the comments section.