I have a late 2013 retina macbook pro. I have been using time capsule and time machine to back up my computer thus far, but I want to get an additional external hard drive (just in case - I worry about losing stuff). I already have a Seagate freeagent drive from awhile back, but it is only NTFS formatted so I cannot use it. Which external drives are formatted for macs? Do you recommend a WD, toshiba, or seagate? Thanks!