Hi, all: My 2008 Mac Pro tower is close to giving up its ghost, and I am thinking about replacing with an iMac 5K. With my aging eyes, the 5K retina screen is so much easier on my eyes than the 23" ACD that I am using with the Mac Pro. My only hesitation with the iMac is the all in one design, which means I don't have access to the hard drive, should it or something else in the iMac fail and need service. I store a fair amount of confidential documents on my drive and can't afford to leave my data in the hands of Apple should the iMac need to go in for service. I've read about FileVault2 as a means of encryption, but wanted to get some thoughts on not using the iMac internal drive at all, and using an external drive to boot from. Specifically, I am looking at the OWC Thunderbay 4 - http://eshop.macsales.com/shop/Thunderbolt/ - which has a fast Thunderbolt 2 connection. I could use the enclosure to house some my legacy data hard drives from my old Mac Pro tower, and I would reserve one of the 4 bays for a SSD drive to boot the iMac. I would clone the iMac internal drive onto the SSD, and keep my data/home folder on one of the other drives separate from the SSD boot drive. In this way, the internal (and not accessible to the end user without major surgery) drive will be kept original and clean, and I don't have to worry about my data if I should need to bring the iMac in for service. Is anyone doing something similar? Any issues that you forsee with this set-up in the long term? Speedwise, I am thinking I should be ok with the fast TB2 connection. Would you go this route? Many thanks.