Having a fmic, I can say that it is more of a "cool factor" part than a necessity. The hood ducting is well engineered and provides sufficient air flow through whatever tmic you choose, and you will enjoy the power gains. With a fmic, you have to maintain it, watch your couplers, and verify things don't shift and start rubbing where they shouldn't. I have piping that has been lightly rubbing on my a/c line and has almost worn through both the intercooler pipe and a/c line. That one snuck under the radar. I had a leak that needed repair discovered on a pre-dyno inspection. The weld for the valve flange cracked and needed to be repaired. And although I would not call it lag, the on/off swith that I had with my tmic is not there with my fmic. Boost comes on a little softer with a fmic. Honestly, if the price wasn't right for the fmic, I would have gone with the tmic. I would not worry about heat soak in traffic. You probably won't have much luck hard-assing your car in traffic anyway with either ic choice! haha