Have you looked at Fall From Heaven?
What these people have done over many months is incredible. They have changed the game so much that it greatly outshines the regular game. You say that Firaxis has fewer bugs, but infact Ffh has been much more responsive and has patched their mod, even for the early stages of the mod. They have dived into the SDK and put in so many changes (just look in their forum and look at their code changes thread to see what I'm talking about) that the game is almost totally different. Because of this the FfH mod has even gotten a post of approval by
Soren, who has designed much of the game.
I will buy Warloards, but the claim that Modders are
"amateurs" is just wrong. They have definitly proven themselves. If you don't trust people easily thats fine, but the Sevomod and the FfH definitly has shown that they more than mere amateurs (As shown in part by how FfH has its own forum).