With the growing share of inverter-based resources (IBRs) in electric power systems, the risk of oscillatory events in the sub-, supersynrchonous and harmonic frequency range increases. Various methods have been proposed to identify critical network conditions and calculate margins in the mentioned frequency ranges for system stability. As part of the publicly funded project “SysStab2030”, a selection of methods, including the impedance-based stability analysis (IBSA), matrix-valued vector fitting, the direct evaluation of state-space models and the quantifying mode damping method (QMD) are investigated. Depending on the method, different metrics are calculated to quantify stability margins, such as phase, gain and modulus margins, as well as damping ratio of modes. The methods and metrics are compared by applying them to benchmark networks. It is found that all investigated methods can identify unstable cases and oscillations when compared to EMT time domain simulations. However, the ranking of the criticality in stable conditions differs between the evaluation of the damping ratio and the other margins. The metrics complement each other since the damping can reveal modes close to instability, whereas low phase or gain margins can point out frequencies at which high amplitude oscillations may occur.