Well I removed the 20g under servo weight and it was amazing. No over rotation from the backend so I could carry a stupid amount of corner speed, it was planted and I could really push the car to the point where the tires were screeching through the twisty bits. It was more nimble because I could get the power down earlier and break later.
I left the evenings racing with a big grin on my face. I now like the chassis to the point that it isn't ever being removed.