I've heard a bunch of theories on car tuning, especially since I purchased a xray, that having a flexible chassis will make the car grip better in corners.

Having run a stock (non-graphite) tc3, factory graphite chassis and an IRS chassis, the IRS chassis was much more predictable in the corners, and also much more stiff.

I'm in doubt on this and I wanted to see what you all think.

My thinking Goes:
Chassis flex is bad. It modifies the camper change in the compression of the car's suspension in unpredictable ways. Esentially the tires will not maintain the correct camber angle to the road during cornering because the chassis is flexing and changing the geometry of the suspension.

This might make it easier to drive, similar to a shorter link with a lower inside camber link pivot point, but not faster.

Basically make the suspension do what you baught it for, control tire contact patch.