Just got a new MBP, installed an OWC Mercury Extreme 6G as my boot drive, and put the 500GB@7200 drive into my optical bay. I have my home directory stored on the HDD. My concern comes from Steam. Steam insists on storing content in ~/Library/Application Support/Steam. So I moved this folder to /Library/Application Support/Steam and used a symlink to point my user version to it. What I'm not sure about is if I've created a bottleneck. Because the symlink is on the HDD and the source is on the SSD, is the HDD bottlenecking the reads? I haven't been able to find a drive benchmark tool that lets you choose which directory to test in, only which volume, so I haven't been able to confirm this myself.