The difference is amount of hook and length. The Ultimate Nirvana has a lower RG core which will start up 1 - 2 feet sooner than the Mastermind Einstein if drilled the same. Also, the Ultimate Nirvana will hook about 2 - 4 boards more because of the ECS coverstock formula. Both balls have a hybrid coverstock and take well to surface changes. I have my Mastermind Einstein with a pin up drilling and it creates a good amount of length with a lot of recovery when moving left into the oil. I have my Ultimate Nirvana with a pin down drilling and it has a little more midlane motion compared to the Mastermind Einstein. I keep both balls at a 3000 surface to smooth out the reaction.