I'd agree with what you found and discovered with DW and CCC, and a Finder copy, from my own experiences.

For the "zero out" formatting option, have a look here:
http://www.macworld.com/article/1141...ard_drive.html
and close by here:
http://www.mac-forums.com/os-x-opera...-yosemite.html

PS: a zero-out or one pass security write/wipe is basically doing the same thing. And don't even think of or bother or doing an absurd 7 pass, that's just super overkill and there for the government paranoid folks!!!