I have looked through the threads in detail and can't find an answer to a query I have, which is in two parts: 1) Work have given me a new MacBook pro and rather than me carry two MacBooks everywhere, I thought that I would run a bootable SSD with my personal stuff on it as I am not allowed to use the work MacBook for personal stuff like email account, video editing and spotify etc. I have run an external SSD in the past as a bootable drive, but I want to know if using this by holding the Alt key down at start-up will create a complete separate 'system' outside of the spy-ware that work will use, or will they know that I am running my own system on the hardware? 2) What do people recommend at the fastest external SSD? I can see that the new macbook pro uses USB-C and I was looking at the SanDisk Extreme Portable SSD, will this be fast enough, or will I have to go for a Thunderbolt drive? Thanks. P.