Baffled by Android storage system...

So, I am entirely confused by the whole PersistantDataPath/StreamingAssetPath/DataPath set up, and I'm not sure what one to use, or how to use it...

I have what I want running in editor perfectly, but its not working on my android builds and I'm not sure why..

When the program boots up, it loads in data from and xml(In the Assets root folder) to make a visible list of sorted objects, users have the ability to favorite certain objects, and on doing so it should re-sort the list, and save out the data in the xml again and have that same edited list remain on multiple launches.

I guess some of my code might help if im doing something glaringly wrong :S

Read In

     public void ReadIn(string soundType)
     {
             string _bytePath;
 
             if(Application.platform == RuntimePlatform.Android)
                 _bytePath = Application.persistentDataPath + "/" + soundType + "Bytes.xml";
             else
                 _bytePath = Application.dataPath + "/" + soundType + "Bytes.xml"; 
 
             XmlDocument _byteXml = new XmlDocument();
             _byteXml.Load(_bytePath);
 
             XmlElement xRoot = _byteXml.DocumentElement;
             XmlNodeList xNode = xRoot.SelectNodes("/ByteList/Bytes/Byte");
 
             foreach(XmlNode _xNode in xNode)
             {
                 string _nam = _xNode.Attributes[0].InnerText;
                 string _dir = _xNode.Attributes[1].InnerText;
                 float _len = float.Parse(_xNode.Attributes[2].InnerText, System.Globalization.CultureInfo.InvariantCulture);
                 bool _fav = Convert.ToBoolean(_xNode.Attributes[3].InnerText);
 
                 _byteArray.Add(new ByteInfo(_nam, _dir, _len, _fav));
             }
 
     }

Write Out

     public void WriteOut(string soundType)
     {
         string _bytePath;
         var serializer = new XmlSerializer(typeof(ByteList));
 
         if(Application.platform == RuntimePlatform.Android)
             _bytePath = Application.persistentDataPath + "/" + soundType + "Bytes.xml";
         else
             _bytePath = Application.dataPath + "/" + soundType + "Bytes.xml"; 
 
         using(var stream = new FileStream(_bytePath, FileMode.Create))
         {
             serializer.Serialize(stream, this);
         }
 
     }

I might have been able to figure this out if I had any idea how to debug on an android.. currently I'm just changing minor things, rebuilding then testing it on my phone :S Any help appreciated.