Originally Posted by
Ualaa
If your software virtualizes the Config file, then there is nothing to be gained from multiple copies of the game. Run the single install, and let the virtualization of the Config file get you your various settings (higher/lower video/sound options). If this is the case, I'd stick one copy of the entire game onto the SSD (or if you're worried about space, you can use SymLinks so 15-50mb of the 15-20gb install is elsewhere).
Since you have an SSD drive, you will likely want your Config, Data and Interface folders to reside on the SSD.
It is optional if you want the entire folder there (which is what I've done on mine), or just these folders while you use symbolic links (symlinks) to copies of your warcraft folder located either on the SSD or another drive. The SSD has under 1ms seek/access times, and faster sequential reads then a non-SSD drive, so with an SSD I would not even consider running other warcraft installs from another drive.
If your software does not virtualize the config file, and you want different levels of settings (ie, A: Everything on, for one-box raiding; B: Most things on for the Master/Lead toon; C: Almost everything off, for the Slave/Follower toons), Symbolic Links lets you have three copies of Warcraft on your system. The main install will be the full 15-20GB. The copied folders (without Cache, Data or Interface folders), will each be under 50MB.