Also you can still run EMET on Windows.
I feel like I know how to reduce the attack surface a bit more easily on linux client systems. Most OEM Windows installations are pretty bad, so I would want to install Windows myself, sans crapware, and with unneeded built in services, apps and hooks and so on removed. If the bootloader was locked, I'm not sure whether I could reinstall the Windows OS of my choosing. Maybe these products have less crap on them though, since the OS image comes directly from Microsoft.
I didn't mean to refer to situations other than personal clients used by me, and I don't really have an opinion about this in general, except maybe: It depends... :)
Maybe. Have they fixed UAC not being security boundary [1] if you are on a default administrator account? It's hard to take them seriously when most software for most users still runs effectively under 'root'.
[1] http://www.pretentiousname.com/misc/win7_uac_whitelist2.html
Can you elaborate on this or provide some sources?
We, as users, have no way of verifying what BitLocker does, if it has backdoors, etc.
BitLocker is secure in that it keeps out the attackers. If it keeps out the NSA is a different story (one that is much harder to determine).