Fudge fulfills its purpose best when it is expressed as simply as possible. I am sure it can be played satisfactorily as a substitute for GURPS, and it serves that function admirably well for those who are not averse to massive blocks of statistics, but is that degree of detail really what Fudge does best? In my experience, greater detail almost always equals slower play, and slower play equals decreased immersion in the role and the setting, because one becomes more distracted by the rules themselves. In other words, heavy rules systems impede actual role-playing. I'm not criticizing those who prefer a more detached style of play, but it would be disingenuous to ignore the fact that Fudge was specifically intended to be a game that emphasized the role-playing aspect and sought to eliminate or minimize any game element that might intrude on the act of role-playing. The default style of play in Fudge is subjective character creation, subjective character development, and combat resolved through "story elements." In its rawest form, Fudge is the essence of simplicity and the perfect game with which to introduce new players to role-playing.
Sometimes a little structure is helpful, too, which is why certain objective game elements can be used to reinforce the game's mission of facilitating good role-playing as long as those rules are minimal. They should serve as seeds of inspiration, not as straitjackets. Broader character traits lead to more creative implementation. Generalized combat rules lead to more imaginative tactics and stunts. Minimized rules lead to maximum ingenuity.
This is why I have been increasingly striving to simplify Fudge for my own design and gaming purposes. Anything that doesn't make intuitive sense or slows down the game I minimize or discard. Anything that contributes to decision paralysis I minimize or discard. Anything that causes my vision to blur I minimize or discard. Games such as Sherpa and Ghostbusters have been very instructive in my pruning of the game. Very soon, I'll have an all-purpose "minimalist" version of Fudge that I can adapt to any genre. Then all I will need is a good title.