I just received my new MBP. Before I bought my new computer I checked my memory "usage" of my 2010 that I was replacing. It has 512GB SSD. Used space was 470gb. I had less than 50gb of free space. For the new machine, I copied every file over manually (with usb drives) including every song, movie, document, app etc. I also installed every program I had on the old computer with NEW installs of the latest and greatest version which require quite a bit more of memory. Somehow, on the new machine, I have used less than 100gb. I have looked throughout Finder on the 2010 looking for files that I might have left behind but I cant find anything. Where else do I look? Why such a discrepancy in file storage space? My trash file is emptied frequently so i didnt loose storage there. Any ideas?