[FFL]

You can't really use a Finder copy to properly clone a startup drive - that's why utilities like CCC and SuperDuper exist.

I'm a SuperDuper fan, myself - I've used it onsite twice this week alone, and I use its Smart Update function in addition to Time Machine so that I have redundant and multi-format backups as well as an emergency startup drive.

As far as data-only speed goes.... if you're command-line comfortable, I'd use one of those, in single-user mode. Otherwise, I'd probably just use the Finder.