You are correct that "enabling hibernation" should have no effect on Windows 7 startup or shutdown performance, though I have no idea how quickly Windows 7 can

You are correct that "enabling hibernation" should have no effect on Windows 7 startup or shutdown performance, though I have no idea how quickly Windows 7 can enter and wake from hibernation with no user sessions open. While this would be easy enough to test, I also don't care: Windows Server 2008 R2 cold boots to a usable desktop in twelve seconds on my machine, which should be fast enough for anyone.