I have a mid-2014 rMBP 2.2, Iris Pro. I did a clean install of Yosemite at 10.10.1 an did in place updates since. Since the update to 10.10.3, I often have slow restart bootups, approximately 1 min, whereas they used to be about 30 seconds. Sometimes, I type my password to log in, and rather than logging in, it restarts again, returning to the log in screen, and then the second time I log in, I get the progress bar and successfully log in. Thoughts?