Well besides what I described in the article, the only thing else I have to go by is the quarter mile. I ran my car last Thursday for the first time (never ran a car at a track before either) and don't have anything else to compare it to, so it's probabaly a poor example to go by, but I'll still share it:

R/T .043
60' 2.304
1/4 15.028
MPH 93.21

It was VERY humid and pretty hot outside (Florida), and I have an autostick. With cooler weather I think I'd get much better times. I think the low end gains and sound make it worth it anyhow... I could never go back to the stock airbox.