Re: SGX -- More than speed
AMD has Secure Memory Encryption and Secure Encrypted Virtualization which encrypts the RAM and keeps processes and VM's completely separate respectively. It is also the path of least resistance, and for SEV doesn't require code changes to anything other than the Hyper-visor which is happening presently. To implement SME in software doesn't require any heavy lifting either.
SGX appears to be the equivalent of AMD's long deprecated 3DNow! instructions (or probably closer to Intel's Itanium) in terms of being setup for non-adoption and deprecation. I don't see it surviving due to requiring too much work to implement. Currently Intel's initial attempt is borked in silicon and still being worked out. Cascade Creek is the earliest release arch now for SGX to work sometime in 2018, To date, I'm not aware of any SGX apps in the wild, given no CPU support. In this case, Intel will likely do what they did with AMD's AMD64 and NX instructions and adopt SME/SEV from AMD, and deprecate SGX like they did with IA64. They're cross-licensed on tech after all since both are using several patents from each other.