When it comes to these programmers it is all about the fuel mixture. Not to rich and not to lean. The problem with locked in maps is that if anything changes then that map is no longer good or atleast most optimum. I am not just talking about mods like pipes or an intake. I am also talking about changes in load like adding a passenger and/or bags. Also, external air density makes a difference. I live in Las Vegas at low elevation. If decided to go for a ride to Arizona then I will be climing atleast 2500 feet in elevation which is a big difference in density. Weather can play with this as well. The auto tuners will constantly measure and adjust your fuel mixture while the fixed map will be much more limited. Unless you are just racing where the conditions are always the same then auto tuners would be the best way to go.