I disagree with Mrjstark. I generally find that upsampling yields a more analog-sounding result. I've had 12 CD players, some of both types, and I currently own one of each. My Creek CD50mk2 doesn't upsample but my Audio Aero Prima mk2 does. And I love both. But in my experience, upsampling doesn't matter as much as the output stage design, so there is lots of overlap in performance between the two types. The bottom line is you don't need to worry about it. Just enjoy the music!
Arthur
Arthur