There were bound to be stories like this from people who bought MMR on the reputation of MM. I don't see your comments as negative - it's your opinion after spending some time with the game.
If you really think you aren't going to be happy with your MMR - sell it. I have no doubt you can readily find a willing buyer. But give yourself a few weeks to see if Medieval grows on you - it's quite possible that it will.
I used to think The Addams Family was very overrated and never "got it" - until I decided to buy one, with the idea I could flip it if I didn't like it. Now I can't imagine not having TAF in my lineup.