Dry electrodes for electroencephalography (EEG) enable studies in ecological environments, social interaction, brain computer interfaces, and neurofeedback. Reported channel reliability, preparation time, and wearing comfort vary significantly between differing dry electrode concepts and caps. We investigate applicability, performance, and comfort reported in a multi-center multi-operator study using Multipin Ag/AgCl dry electrodes. We compare the performance of dry Multipin EEG caps and gel-based EEG caps, comprising 64 channels each, in recordings of resting state EEG with open and closed eyes, eye blinks, and visual evoked potentials. Equivalent studies were carried out in six countries involving overall 115 healthy volunteers. We compare electrode-skin impedance, channel reliability, and subject comfort reports between cap types. Furthermore, we investigate the eventual impact of operator experience and preparation time on the performance metrics. The average impedances of the dry EEG caps are four to ten times higher than those of gel-based EEG electrodes. The average channel reliability of the dry electrodes is 15 to 20 % lower than for gel-based electrodes. No considerable differences were observed between the gel-based and dry electrode EEG recordings after exclusion of bad channels. The preparation time of the dry caps is considerably reduced, and the comfort is slightly reduced. All findings are in line with previous publications, but exact values vary considerably between operators. The considerable variability of the performance metrics across operators is suggesting a strong influence of operator training and experience.