What is better for text reading and writing?

What is better for text reading…

        TextAsset content = Resources.Load("tempTextFile") as TextAsset;
		string tempString = content.text;

or Using System.IO operations

        using (FileStream fs = new FileStream(path, FileMode.Open))
				using (StreamReader reader = new StreamReader(fs))
					string tempString = reader.ReadToEnd();

The thing is that I need to write back in to the file as well… for that I eventually have to use System.IO operations … or is there a way in unity libraries for achieving that as well?

I think in the first line it depend on which system your game should run. For mobile and read only I would prefer Resources.Load because I think you could get perhaps some trouble with a streamreader on an IPhone.