rsync -av --progress /path/to/722/wav/directory/ /home/myuser/wav/myshow
This would rsync everything from inside the /path/to/722/wav/directory/ directory to the /home/myuser/wav/myshow directory and print progress. Pay special attention to the addition and omission of forward slashes on the end of the paths, they are significant. Example syntax is in the man page. I would try it on a test directory the first time. The one downfall I've found is that since rsync is so I/O intensive it sometimes will spin an external drive into being disconnected. This happened to me rsyncing to an ipod as an external drive many times. The 722 is probably alot burlier as far as it's HD so I would guess you won't have those problems. Otherwise just copy and compare. In addition to the md5sum tool you do have other ways to compare files faster on linux as well. The cmp command is a quick way to compare them, diff is another, md5sum works fine as well. They're all operating on basically the same principles. You'll find that most devices that present themselves as raw external storage are extremely easy to use in linux, plug 'em in and your usually good to go after the kernel recognizes it.