Ok, I'm new to the Mac world so please bear with my ignorance. I just got my 15" rMBP and plan to dual boot via Bootcamp between Windows 8 and OSX for the time being. For the short term (while I determine which OS I prefer working in) I will load Lightroom (and eventually Photoshop) in both OSes just to see how it works in both. I've purchased a WD 2TB USB 3.0 drive. I plan to keep my photos and Lightroom catalogs on this drive and use it back and forth between the 2 OSes. It came formatted as NTFS. I understand OSX cannot write to NTFS. I was considering formatting it as exFAT, but I've just read that iPhoto only works with HFS+. My question boils down to....do I care if iPhoto can't read the external drive? Does any of this matter? If I'm using LR, is there any need for iPhoto? Will I prefer iPhoto for lighter browsing of photos? If so, maybe I'll just keep a small batch of my favorite photos on the local SSD for that? Any thoughts or feedback is appreciated. FYI, I have a 2TB NAS that I'll use for Time Machine backups and backing up the WD drive (until I run out of space and need to add another). I also have Crashplan for offsite backups.