I've stopped using the mobile Vox player on iOS because there's not a good way to get to the end of the list. I have my library arranged by Artist, and if I want to listen to something at the end, alphabetically, it takes a long time to get there because I have to swipe 30–40 times. This could be solved by using an index list (that alphabetical sidebar thing used in, for example, the Contacts app in iOS).
The other way to get to the end of a list could be searching, but that's pretty wonky as mentioned in this post: http://support.coppertino.com/discussions/suggestions/1326-searching-for-artists
I'm really loving the direction Vox/Loop is headed. Keep it up, folks!