This paper presents the results of a study to assess the timing measurement capabilities of e-beam probes and how they compare to mechanical probes in terms of sampling time, accuracy, and repeatability. Analysis of the data indicates that the transient response of mechanical probes is prone to overshoot and ringing, which contributes significantly to measurement error and uncertainty. E-beam probes, on the other hand, are subject to charging effects and interference which, as the authors show, can be effectively eliminated, facilitating high-speed timing measurements accurate to within a few picoseconds.