There isn't much. It all depends on how much music you need to carry around as opposed to the sound of your music. It is kinda why I almost got a regular 925, I thought didn't need to carry all my pictures around and I could manage the smaller space the same why I do with my 8X's music. But once I couldn't get the 32GB version, I decide storage was more important. Especially since there isn't a huge drop off from the 925's camera to the 920.
I lugged around a ton of music on my 810 and the sound quality was OK. I like the sound of my music on my 8X better. But it is up to you to decide, as your SD choices are between Nokia and Samsung.