Things to not do: Don't start the copy when you've got the drive mounted (Like I did ).
Oh, god, yeah... that's bad.
And yeah, you'd want the "metadata" folder, as this is ABSOLUTELY necessary. This contains the drive's information, including revision and "geometry". Without it, you won't be able to mount the drive. Period.
And yeah, seeing all the usage info is very nice.
(but I'm a "progress bar nerd")