Less freedom is no freedom : Linux boot and UEFI
nicubunu.blogspot.com
nicubunu.blogspot.com
Windows 8 is using UEFI and boots in 20 seconds. If i select Linux Mint from the GRUB it boots too. (actually this is the same computer as mine and it boots very fast with Windows 8 http://en.wikipedia.org/wiki/File:Win_8_Runing.ogg)
Maybe the concerns are about the ARM version?
Of course, the problem is whose keys will be in the trusted set in your BIOS? The ones from Microsoft for sure (and they will happily sign anything they are asked to by US intelligence), and probably something from main board vendor. And here is where the fun starts: you wont be able to boot final version of Windows 8 without Secure Boot, but Secure Boot won't load GRUB. So you need a trip to BIOS configuration (IF your vendor was kind enough, which may be obvious now but may not be so in a few years) on every OS switch.