ADDED 6/9: Some Insiders have reported having their installation of this build getting stuck or hung at around 33%. If this happens to you, you will need to restart your PC and have it rollback to Build 16199 and wait for the next build with a fix.
ADDED 6/12: We are investigating an reports of GSODs with inaccessible boot device on install, and the Windows Update error 0x80070643 after rollback. See this forum post for more details.