Just ask the Ramones.
Spector's collaboration with the Ramones was ill-starred. Johnny Ramone complained that Phil spent 12 hours contemplating the opening chord of "Rock and Roll High School." And Dee Dee Ramone said, "He wasn't the most friendly guy I've ever met. He tried to be friends, but then he had guns on him, and he wouldn't let me out of his house for a couple of days. I never met anybody [else] like him and I hope I never do."
A musical genius, but a complete nutjob.