Is there much of a weight saving if I were to change my oem suspension system to a Teins for example? Cheers guys

 

according to info at famos shootout article tein monoflex saves ~5lbs in total comparing to CR's suspension.

pretty much negligible IMO.

 

Saving weight on your suspension is always a good thing. The lighter your suspension is the better chance of your tires staying in contact with the road surface.
Coilovers are part sprung mass and unsprung mass so you're not getting a weight savings of 5lbs of unsprung mass, it might be more like 2-3lbs and 2-3lbs of sprung mass.
That doesn't mean you should shop for the lightest suspension system because in the end the damping system is the most important part and a lighter suspension system if damped incorrectly can be worse traction wise than a heavy suspension system that is damped correctly.