I've got a 750 gb drive in my late 2011 15" MBP. I've got over 740 gb of data on it. About 420 gb are audio files. I've also got about 170gb of "other". I can't seem to figure out what that is. But I think the best option is to upgrade to a 1 or 1.5 tb internal drive. I checked New Egg, and it looks like there are no 7200 drives over 1T. I also see the "SATA 3" and "SATA 6" specification. I'm not sure what those mean. Im curious whether there are any less expensive and perhaps longer term options. I've got a 3 tb external which I used for both back-ups and storage of old media/photo files. I need my large audio file to stay on the laptop, because I used the laptop as my music server -- streaming through an ATV. Even if I moved all of my photos off the laptop, I'd only save about 15 gb. (I already moved about 30gb of old photos/videos onto the external drive.) I have no idea what is making up the remaining 250 gb or so of data. I check my applications, and more are a few gb or less. My downloads and documents folders are only a few gb.