All that being said - if you NEED to run Windows on a Mac - or a PC that is supposed to run Linux as its main operating system - you have chosen the wrong main platform for your daily work. You should have stayed with Windows, period.
I NEED to run windows on a mac (visual studio), but I also NEED to run xcode. I don't want 2 machines, and I want to easily share data between the 2 platforms.
There are use cases for parallels/vmware, otherwise why would people buy it (Also its a lot cheaper in hardware cost and support/backups/restore time to have a couple of virtual machines on one set of hardware, regardless of what operating systems are actually in play).