Stabilizer Bars - Do they worth the money?

[Apolan]

i know the exact phisycal aspect of how anti-roll bars / sway-bars / stabilisers affect suspension dynamics; it is the strut braces im unsure of, thats why i ask. The way i see it they just provide the additional rigidity to that part of the chasis, so the "angles" of the chassis remain the same under load, resoulting in better performance of the existing suspension. But i wondered how does that affect suspension performance exactly (like in aproximate numbers)..