To get the best balance, it's important that the sway bars, springs and shocks complement each other (and that doesn't mean talking to each other every morning saying how nice they look).
If your front sway bars are too heavy for the spring settings, as already mentioned, you will end up with a car that handles like a dog, understeering like buggery. ( I know, I did it on my HR). You will find that there is usually more than one diameter sway bar from the factory for each model (ie 6's have one setting, 8's another, utes another etc.) because of the differing body weights and spring/shock settings. Just as an example, the early 6 and 8 cylinder Commodores had front and rear bars, the 4 cylinders didn't have the rear.
They're certainly not a last option - rather, they are a very vital component.