Has anyone reflash their ECU? Also is there any power gain from it?

 

I haven't heard of anyone doing that nor of any files that are available to do it with. I would think that a number of benefits could be gained from it, if the right programming changes were made to it. The most obvious one would be to eliminate the gas pedal delay. Now whether more power could be gained from a change, is unknown, though I'd speculate that it is likely that more power could be gained but often a gain comes at the expense of something else, like gas mileage.