jeff @ tgs said it best, it really does help provide consistant power delivery. I put mine in (just ets 5") right before 100* F heatwave this summer, the results were very appreciable in my daily driver. Once the stock IC gets heatsoaked it takes quite a bit to cool back down and it will soak again with just a good hard pull. That problem is greatly minimized with an upgrade.
FWIW, and really just a coincidence, I happened to pick mine up from top gear solutions. Had some issues with delayed delivery from ETS, but they were very good about keeping me aware of the lead time and were willing to work with me to make up for any problems the delay caused.