What's the best recommendation to boot Mountain Lion from external SSD via thunderbolt? Are there wake issues from sleep? Is TRIM supported or even recommended? Can I make it default boot from external SSD without choosing? Have there been any reported issues at all booting Mountain Lion from external SSD via thunderbolt? I was looking at getting a backpack shelf for the back of the iMac or even fabricating one to hold an SSD. So it's not visable. I decided that I don't want to open up my 2012 iMac 27" to add an SSD. That's why I'm going external. I've read several different threads on this and just wanted some user experience from people that have done this to the 2012 27" iMac.