You don't really have to experience a 'problem' with it, but indeed it can be better. With the standard rear beam you get a lot of negative camber which reduces traction and excessive toe in which causes understeer. With an adjustable 6 degree beam you can correct both camber and toe. And the 6 degree part of the beam will also cure a lot of understeer as it has much less bump steer than the standard beam.

On the front a very low ride height with standard 2wd Sapph knuckles causes a low front roll centre which creates more body roll and again understeer. Fitting 3dr knuckles solves this and gives a much nicer steering feel as well.

But of course it depends a lot on what you find important. I find the handling of the car more important than the actual power, as I enjoy good handling more than huge amounts of power.