I made the transition to using an external SSD (Samsung 840 256GB + OWC Express USB3) for booting & the internal Apple 1TB for data. Now the SSD won't boot. I booted from the Internet recovery partition and Disk Utility is telling me the SSD has "Invalid Node Structure" error that can't be repaired. Data Rescue only recovered about half the data from the SSD so I'm bummed. Do you think it's an SSD problem or an enclosure problem? I plan to RMA both if I can but I'd like to know if one of them should be replaced with a different brand/model. Thanks!