I would give zero stars if I could.
My wife has a 403B retirement account that was with a company that was acquired by Mass Mutual. She has been trying for over 4 months to get the funds transferred to an IRA that she has with Vanguard. She was sent form by Mass Mutual to complete, which she did, and then was told that she completed the wrong forms.
She was sent the missing page and was told to complete it and send it in, which she did. Then she was told no, she needed to start over and complete the complete packet of forms. To reach someone she is generally on hold for 30 to 45 minutes.
I used to be the trustee for a 401(k) plan when I was working. I have never seen such piss poor service when it comes to a retirement plan.