I've had lots of luck setting up Linux boxes as file servers and cross-compilers at work, it always seems like Linux takes too much effort to use as a home PC. I have two computers at home. One runs Linux and the other runs Windows. It seems like I spend more time fighting with the Linux one than using it. Windows, is far, far from perfect, but I usually have far less trouble using it for what I do at home.
Trying to do the things I do at work on Linux using a Windows box would probably be equally painful. Sometimes different tasks require different tools.
Oh goodness Fedora Core is not for the faint of heart, I love it as a power workstation but its not my first choice for a desktop.
I've been running Ubuntu as my main desktop OS for over a year now and rarely boot Windows at all. First with Dapper Drake and now Feisty Fawn. I skipped over Edgy Eft and will probably do the same with Gutsy Gibbon. I love the customisability of it and the Beryl/Compiz Fusion 3D Cube are awesome eye candy. Not to mention that I love having multiple desktops with open applications available on a rotating cube that spins with a simple roll of the mouse wheel. The only apps that I've found it hard to replace are mostly video editing ones. I have been messing around with Cinelerra, Kino and DeVeDe lately with some success.