In a recent study by Cleo et al. (Article Usability and acceptability of four systematic review automa...
) the performance of four systematic review automation software packages (Covidence, SRA-Helper for EndNote, Rayyan and RobotAnalyst) were compared. SRA-Helper for EndNote was ranked highest due to its efficiency and acceptability.
Have you tried to use a trial version of Covidence? You can screen there 500 refs for free. From my experience, there are several pros of Covidence: resolving of conflicts (easier than in Rayyan), deduplication, and pair-screening (calibration for more than 2 people is easier in Rayyan). But my advice, before you buy a licence, use all of the trials version (Rayyan is for free at all).