Does fitting twin piston KS callipers make much of an improvement?? when fitted to say a KR or non ABS TS 6, my local Mitsi. wrecker says no, marginal advantage at best

I've owned both a 4 cylinder non ABS single pot front caliper TS and a V6 ABS twin pot TS Magna. There is a big difference in braking ability, even though the V6 is a wagon and the 4 cylinder a sedan, but I put that down to the different tyre sizes on the 4 and 6 cylinder TSs. Probably better to keep the single pot calipers and upgrade brake pads for improvement.

Slotted Rotors fitted to my KR wagon have made a great difference I would highly recomend.