Reason for multiple sets of WoW files vs a single set?

So I run 5 instances of WoW from a single wow installation, everything runs fine. I have seen several posts about making 5 copies of said wow directory and running each wow instance seperatly through the copied sets of files, is there any particular reason one would want to do this? whats the advantage?

From my searches I have only found posts regarding why you should setup symbolic links between the separate wow directories, but not actually why people make copies of the folders in the first place vs just running all instances from 1 directory? Just curious

I wondered the same thing. The only one that makes sense (to me) is separate hard drives. From the perspective of the wow executable or the operating system, a symlink is the same as a separate directory. It's only advantage is saving disk space. I've tried separate directories and symlinks. I ended up just running the same executable multiple times. What I've noticed while loading is one instance (seems random) will load faster and all the others will load at the same rate but slower than the first. This may be due to hard drive cache or the operating system recognizing the same data being requested by multiple programs. When I had separate directories for each instance, the hard drive was jumping all over the place trying to read essentially the same files in several different places.

In the end, until someone can post measured performance figures for each case, just do what you feel works best for you. It's all just hearsay at this point. I like just one install for the ease of keeping things updated.

if you symlink only some of the folders it will keep the installs "seperate" so to speak so you won't overwrite the settings of the other copies. That's the only reason to do that.

I have 5 WOW-Folders. I did it because i hat read/write errors. Also, some Addons do not work, if u use them from within one folder.
On the other hand my system runs sloppy, i will have to inspect my ram-management, maybe i have a problem there. How much ram u guys have for 5-Boxers?

Ah yes, the settings. Those are on my multibox todo list. The symlinks would definitely help there.

I have different settings for solo play and multibox play. For instance, I have a Rogue I do arenas and such with, if I'm running him thru an instance with friends or something he has his own UI setup, addons that I don't use with my boxers, etc. With my boxers, it's all different, that's the only reason I use different wow folders.