OK, update time ... this Seagate 4tb drive is up and running with the proper size reported back after reformatting: 3665.59GB . I think what may have happened is that when I added the drive and began its formatting i aborted as I wasn't sure it wasn't going to format the first drive in the 325. I do believe the wording could be clarified in certain spots - that no data is lost on an existing drive when a new drive is added and formatted as a Standard drive.