I recently updated my OS X to Mavricks and didnt notice any problems. If I select EFI, it jumps into GRUB 2 and I can select which Linux versions I want to load. When I boot and hold down the option key, I have four choices: 'MAC', 'Windows', 'EFI', and 'Recovery'.
I then installed two Linux version, with Ubuntu being the last one because Ubuntu supports EFI install. The Linux partitions cannot be read by Windows, so it doesnt really matter if they are listed as free space. Under Windows, I an see my Windows drive, Shared Data Drive, and my OS X drive (might be read-only thought). Anything below 2 and Windows will only install in BIOS mode, even it it is the 64 Bit version. I installed Windows 7 under BIOS mode, because I have an older machine with EFI version 1.8. Then I installed OS X using the same Boot-USB. All partitioning was done using Disk Utility. I seem to remember that i has used Bootcamp only to make the Windows Drivers DVD, but nothing else. I didnt not use Bootcamp to install windows.
