u/JoMamaLickinMaNutz

Here is why:
I just finished cmm and I always thought it would be way harder.
After finding 4 guys on the gtao dc we got to it and failed the first three times while doing the prison break finale. At that point we swapped out one guy who was not taking the challenge seriously and found another guy wanting to do cmm in one sitting.
He was an actual gamechanger because he told us that if anybody died we had a chance of saving our progress by quitting the game really quickly. With that trick we got through all the setups and heists with only 4-5 deaths total and completed cmm after about 15 hours.
Criminal Mastermind is not hard if you are not a total newcomer to gta online but it is one of the most exhausting challenges to do in the entire game.
To everyone who wants to try cmm before the end of gta online do it.
With enough time you can and will finish it and the feeling of finally completing THE challenge in gta online is worth more than the 13 million dollars it pays out.
Good luck to everyone trying this insanely long challenge.