Yea , I think They are fine for Macs. I have a Lacie 1TB and it works great. Honestly though I also have a WD MyBook Studio Edition 500 Firewire 800, or USB that not only works well but I use it as a bootable startup drive, and if I'm not mistaken It's cheaper. But haven't checked lately. Be careful though, you didn't mention this, but not all drives are capable of being a startup drive, but both of these are. PS. Just for the record, I've never used the eSata connection on the MyBook, so all comments above related to WD MyBook are Firewire only(Don't think you can create a startup disc from USB, but not 100% sure). Both as backups with Time machine, Backup, Silverlight...etc.. both are really good. Snakedoctor......