Tree-based model editors and hybrid graphical-textual model editors have advantages and limitations when editing domain models. Data is displayed hierarchically in tree-based model editors, whereas hybrid graphical-textual model editors capture high-level domain concepts graphically and low-level domain details textually. We conducted an empirical user study with 22 participants, to evaluate the implicit assumption of system modellers that hybrid notations are superior, and to investigate the tradeoffs between tree-based and hybrid model editors. The results of the user study indicate that users largely prefer hybrid editors and are more confident with hybrid notations for understanding the meaning of conditions. Furthermore, we found that tree editors provide superior performance for analysing ordered lists of model elements, whereas activities requiring the comprehension or modelling of complex conditions are carried out faster through a hybrid editor.