Well it kinda depends on how your using your systems, more so with command line type stuff or typical office use
I usually perfer it when it's Windows as the primary OS and Linux in a VM, so anything linux needed just requires a VM bootup and Windows is there for everything else including any AD or MS Exchange setups going. I've also encountered numerous situations that you find out a program is windows only and well your kinda stuck if you just have linux going, but in the end it can also be safer if configured right and Windows in a VM instead too so all in all its a matter of asking which do you want your primary OS to be?
Additionally letting linux be in the VM allows users to have higher level access (such as sudo) without endangering anything, unless your holding onto national secrets etc and if they mess up while in sudo its only a matter of deleting and picking up the pre-configured linux vm image to restart, while you'd need to be more careful if its the primary OS. Linux tends to boot faster though and if you got a million things running stay stable longer than windows(a good reasonable windows install though is just as stable over long time periods), Windows 8 however will give that a second consideration though.
Linux also has the problem that there are 50 trillion flavors and (sometimes) downloads are set for red hat, or non red hat, and other various splits there.. Linux is also trickier with anything graphics related, but can work if its done right
My experience with Linux tends to boil down to, it work wonderfully if it works, and can turn into mega uglyness if something doesnt work right.