Some contemporary control strategies for active and semi-active suspension systems originate from Linear-Quadratic optimal control theory and linear full-state-feedback concepts. In case of a respective selection of the model states, the LQ-optimal control law involves gains on relative displacements (spring-like gains) and gains on relative and absolute velocities (damper-like gains). These gains are merged with the parameters of passive suspension spring and damper and represent equivalent suspension parameters, which are further analysed based on their effects on the behaviour of the suspension system. The (semi-)active control strategies Skyhook Groundhook Hybrid as well as Extended Ground-Hook can basically be regarded as modifications of the full-state-feedback concept the former as output-feedback control, featuring only the damper-like gains, the latter as an extension by a disturbance feedforward control , and the respective control laws are equivalently formulated as a set of equivalent suspension parameters. Inherent characteristics of these control strategies regarding aspects of ride comfort, road holding and rattle space requirements are thus derived from the characteristics of LQ-controlled suspension systems of a quarter-car and a half-car vehicle model, respectively. By means of the quarter-car model, the concept of equivalent suspension parameters is introduced and fundamental properties and limitations of the control strategies are discussed with reference to the conflicting demands on the suspension systems. Symbolic calculations of respective Pareto-optimal solutions and frequency-selective analyses based on the relevant transfer function of the model allow some distinctive conclusions. Investigations based on the half-car model focus then on coupling effects of the front and rear axle as well as on frontrear coordinated setups of the suspension and control parameters with main emphasis on ride comfort. For both models it becomes obvious, that main features and findings, which build on the knowledge of tuning passive suspensions and rely especially on the broad experience from practical road tests, can be transferred and applied advantageously to active and semi-active suspension systems as well.