1. Target audience, Terms and Licenses (obviously). See more on this on relative product official pages.
All the comparison below is based only on file contents between two medias and does not include differences in folder names, shortcuts and/or registry entries.
2. OPK DVD is bootable and thus it includes the following files and folders. AIK DVD does not—and that's why its media is quite smaller.
3. Branding. The following files are different.
(The last file is obviously located only on the AIK media and not in the OPK).
4. Documentation (also obviously). Here's the difference in what's provided with both kits. A lot of AIK documentation is available online and is not included into the media.
5. OPK includes the following items that are not available in AIK.
5a. Microsoft Windows Recovery OPK Configuration Tool (WinReCfg.exe).
5b. The Windows Recovery Environment feature package for Windows PE (WinPE-SRT). It provides a recovery platform for automatic system diagnosis and repair and the creation of custom recovery solutions. It includes
the following Optional Components (OC).
6. Code samples. They are a bit different between the Kits. I have no idea on what all these files are about so here's just the list.
6a. Help Customization.
6b. Mobility Center Customization.
This is available in the OPK only.
All other content is identical. Including .\Neutral.cab (that contains the vast majority of tools) and
.\WinPE.cab (that is different for some reason but its contents is absolutely the same).