I know that v4 works without any hassles. As v5 is new, I did not want to take the chance that something may go wrong because of the amount of files that needs to be processed.The v5 batch manager supports drag and drop. If you drop files into the UI it will launch the Add dialog with all the files selected. Although I'm not sure if it can handle all 700 at once, that's a lot and may overflow the buffer or the list. You may want to do it 100 at a time just to be safe.
Edit: Didn't realize I was in the v4 forum. You are free to try the v5 beta if you'd like.