I know the question was pointed towards NRW, but I used to have a very similar set up. The lag was very minimal, I could not tell ANY difference. I think you would need to have a higher HP setup to really notice any lag. I really liked the performance out of the Racer X.
I switched to a AVO TMIC, because I was getting a highyway drone that was bothering me, and it was because of the Racer X. The car is much for comfortable during highway travel with the TMIC. I have not gotten the car retuned yet, so I've got a serious performace downgrade.