There is one thing. These devices are not "storage." Just copies so be sure whatever you decide it isn't the last copy in existence of what you can't lose.
The newest Apple OSX will read and write to your Windows 7 NTFS formatted volume with no troubles UNLESS it's corrupt in some way.
I want a backup drive to store off site. My win 7 box, which I just abandoned for iMac, has a new 1TB drive that I want to put into a USB enclosure for use with the Mac, for a shadow copy. Want to keep old pc data on there too. Problems?