I changed out the earbuds that came with Shuffle, in favor of Skull Candy in-ear ones that do not dislodge with movement.
Old player also wins because it's never had a problem playing any of my tracks. At least 2 or 3 of the tracks (so far!) either didn't play except for a repeated grinding noise, or only played one level of track, the backbeat (I am pretty sure those were mashups). I'm going to try and synch those again, but am not sanguine - you would think the purportedly highest tech out there would be able to handle something put together by a professional DJ!
It's a pity, because I like mashups a lot for working out, particularly the complex ones; I can listen to them over and over without being bored; there are a lot of songs included in, say a Mashup Germany track, and there's almost always a steady beat laid down behind, which is great for cardio. It's like using Dance music (which I also do) only much less repetitive.
Finally, old player wins because it's much harder to accidentally push a button. When you manipulate the clip on the shuffle, it's difficult not to hit one of the buttons for volume or track.
Good things: Shuffle is very small and light. I might repurpose it for journeys instead of gym, or for carrying around on a day-to-day basis...except it's not really flexible enough for that. I think it's going to end up being backup to my other players, the one I love and the one that I tolerate.