From your description you have de-tuned the Insight to much a more aggressive driving style.For the last 37000 miles I've have only been able to get an average of 53MPG. So I have tried to improve the engines ability to breath and exhale or intake and exhaust flow.
Better: as long as your style doesn't begin to take additional advantage of the increased performance.
Worse: if and when you decide to try and achieve the ultimate MPG performance the Insight is capable of.
The intake resonator is more than just a noise reducer. You can achieve mid single digit performance improvements if the intake is tuned to a specific resonant frequency. To peak engine torque and HP at streetable RPM's a correctly restricted exhaust systems has similar benefits.
Colder intake air temps (IAT sensor reading) below a rather warm 120ish appears to narrow the lean burn window.
With the Insight the peak MPG performance point is rather narrow. Consistently drive outside the envelope and you'll see correspondingly poor performance. Make the envelope bigger (as you apparently have) and you reduce the upper MPG potential.
Not a criticism. Just an FYI for others looking to get ultimate MPG.
John K. Bullock
aka. Insightful Trekker
78.8 best tank avg.
94+ best one way commute
87+ best round trip commute