I thought my speed in the quarter was off, too, compared to the ET. However, with the 4+, I felt like the car ran out of breath around 5700 RPM in 3rd gear but it doesn't shift until 6200. I honestly think I would have had a higher trap speed if I could have shifted to 4th gear a little sooner. If I recall, it doesn't shift into 4th until nearly 100 MPH.
With the 4+, I got the highest boost in 1st gear, a little bit less in 2nd and still less in 3rd. I am not sure why, but that is what the gauge showed. It seems that with the 4X, I get the same boost in each gear so I think it will be better. I just haven't had a chance to run the new tune all the way through the quarter. The last time I was at my test site, there were deer beside the road so I wasn't too comfortable doing triple digit speeds there.