A very interesting read, indeed... Image may be NSFW.
Clik here to view.Image may be NSFW.
Clik here to view.
Personally, at the current stage of things (for example, no Apple Boot Camp support for external drives, etc. etc.), I would probably choose one of the blue Hyper-X 3.0 USB flash drives, which have very good specs and "reasonable" prices:
http://www.kingston.com/us/usb/personal_business#dthx30
BTW, I tried to create a Windows To Go drive (with a traditional external USB 3.0 HD) from within a Fusion Windows 8 Enterprise VM, and all went well: but then it didn't work "natively" on two of my Macs (it booted with the 8 logo, configured something, but then only a black screen...), so this still seems to be rather unsupported.
The Hyper-X Keys also have a great look from the design point of view...
The only problem might be total endurance, as they probably are designed as data drives, rather than OS drives (but with 5 years warranty: good!): well, running VMs off of them should be OK, hopefully...