I ran a D&D-like (not heroic fantasy, D&D-like) and a modern X-files-like game using Savage Worlds. I feel the X-files game was a success, but The D&D-like never felt like it was firing on all cylinders.
The difference I found was that the X-files game had fewer combats and more non-combat encounters. The Savage Worlds system is fine for the occasional quickly deadly combat, or the occasional PCs show how awesome they are through beating up mooks scene, but it is not engaging enough on its own for a D&D-like: this adventure is 8 combats strung together plus a non-combat encounter for flavour.
The non-combat encounters were fun and fast, so I consider the X-files games a success. BTW, I also have the Accursed sourcebook, and I absolutely love it as a sourcebook, despite the fact that I have never played it.