I agree, I play many many lotow's games for 3 years with the basic campaign system and it's good enough.
Now, I have posses with very high Infamy Rating and heros who are quite like legends, nevertheless our games are still exciting and radically different from ones with low IR.
For a convention in Paris, I made some card (like Showdown) based on Luky Luke. It was given 1 card for every 15 IR points of difference. The feedback was good.