If it's just not for you, and you can't get into it, or forsee liking it in the future, put it up on Ebay. Unlike others who have posted, I don't consider ANY workout priceless, and gladly get rid of those that don't suit me, even Cathe's (I've gotten rid of Kick Max, Stretch Max, HC Extreme, CTX with no qualms). There's no use keeping a workout that you'll never use, and getting some of your money back on it will allow you to buy others that suite you better.
(Though I will admit that I got rid of IMAX2 long ago, and just recently reaquired it, after figuring out that I can modify (by modifying IMAX3) and enjoy it that way (I HATE pivot moves, and decided to remove as many as I can from all my workouts---I like them much better now).
Though trying IMAX3 ONE TIME really isn't a fair trial of it, especially since it's the choreo that threw you off. I never get all the choreography down the first time out--85% of Cathe's choreo,usually-- and sometimes find that if I go back to a workout when I'm in a different mood, I like it better. Preview IMAX3 before trying it out one more time. Decide whether you just don't like it, or if maybe working up to doing it would be a good challenge for you, THEN decide whether you want to get rid of it or not.