In this paper, different technologies of distributors for trickle bed reactors were compared, in terms of intrinsic performance of distribution and resistance to tray unlevelness. gamma-ray tomography has first been used, in a large column unit, to visualize gas liquid distribution just below several tray technologies. Results obtained show a better distribution performance under multiaperture chimney trays, in comparison with gas-lift and bubble cap systems. Then, a specific cold mock-up was designed in order to mimic tray tilt between two tray elements. Sensitivities to tray unlevelness of both gas-lift and multiaperture systems are comparable, far better than the one for the bubble cap system. Multiaperture chimneys have indeed excellent behavior at nominal conditions, while gas-lift technology is interesting for its ability to behave similarly over a large flow range. Considering those results, some guidelines are finally given for the choice of the distribution technology.