Every capacitor has its advantages and disadvantages depending on what characteristics are most important to the user. This chart provides a general concept of capacitor technologies cost per µF of capacitance and cost per mΩ of ESR. Multillayer ceramic capacitors for example are very cost effective for ESR, but relatively expensive for capacitance. The inverse is applicable for conventional wet wound aluminum electrolytic capacitors which are expensive for ESR but very low cost for capacitance. So why use an "SP-Cap" instead of another capacitor? "SP-Cap" provides the best cost performance for moderate amounts of capacitance, in the hundreds of µF, with low ESR in the single digits and low teens.