Normaly a bit count would do. As copying, the bits are counted, an indication would be same bitcount.

That is why I say: Copy something on this drive, a song, few images.
Then go to the copied files and access them.
If they are allright, the rest you will copy, has to be allright also.

Is there any way to specify a directory not to include? Because if I have an NFS drive mounted, and then I try to copy everything to that mount point, I'll eventually end up copying the contents of that directory to itself, and will most likely lose data...I looked at the man page for 'cp' and didn't see anything about it.

As I said earlier, I've been migrating so many times, I lost count.
All things that are important, I store in one 'suitcase' directory, which can simply be copied to whereever drive I want to...
I know that my /home dir, which is on a seperate partition, contains all app-settings, so when i install new, all my previous settings are the same as i configured them earlier...
So I like this Linux feature very much, as windows does not has it, and allways is a lot of fuss to go trough, when installing again.

And also, I prefer 'clean install' to messy old installs to put back again...

The time this takes, the way you want to do it, is simply not availlable to me, and mostly not satisfying..

I like fresh, clean and new, without mistakes and faillures, from previous installs....

But everybody has to do it the way he/she wants to do it, that is my humble opinion...

Personally I prefer to use tar or cp -a when I need to backup my linux partitions. You'll probably need to use the --one-file-system flag to tar so it wont backup /proc for example.
If you use dd you'll grab the underlying filesystem data as well and can't change to another filesystem type(jfs, xfs, reiserfs,reiser4 etc) later.