[GraemeJ]

Well if I could keep my sheets in dropbox and view them in mobilesheets, I wouldn't fill up my tablets free space, and still be able to access my music with all the functionality of mobilesheets

I use Dropbox a lot but, once the files are in MS, I delete them from Dropbox.

If you keep everything in Dropbox, then you are still filling up your memory. To keep the functionality of MS means moving the files into MS anyway, effectively doubling your storage requirements, You might just as well keep the files in MS.

If you only access your Dropbox via wifi, you are relying on 'net access wherever you might be (and plenty of venues wouldn't have it).

Storage requirements for MS are pretty low and you can always used an external SD card if the internal memory is that small.