Heh, funny thing, toward the end of my stint playing Minecraft, even mods got boring for me. Most of them ultimately boiled down to spending oodles of resources to do repetitive tasks in your base... and once you reach the end of the linear progression, you're left with overpowered equipment and nothing to really do with it. While I did like Railcraft in particular (I really, really like trains, okay?), rails are completely impractical compared to the teleportation/flight mechanics introduced in nearly every other major mod out there, thus no one else on the myriad of servers I played on was really that interested... not to mention there is no good reason to build any sort of transportation system, as resources are more or less homogenous. </ramble>
Anywho, I myself have done this once or twice mostly because it's a very brief way to convey the gist of the game without having to explain what a voxel is. Sad, but what can you do?