after i fitted the 1242 in mine i ran around for a day or 2 with out a brace on and the car wandered all over the road and the roll and understeer was dangerous, i put the upper brace on and it tightened everything up and understeer was almost nil, but still there, i have now fitted my lower brace (sacrificed ground clearence) and for the first time driving my car i am now geting a touch of oversteer but that will be sorted when i fit my poly bushes in the back (thing i have a dead bush lol)
imho they are one of the best mods todo but there again thats me lol
buy one and try it, everybody drives differently and the same mod can be different for everyone