I would say get it! I sent 5-6 letters of recommendation to every school I applied to. 3 were the required science/faculty letters and the rest were recommendations from supervisors at work or physicians I know personally.
One of the work ones was from someone who knew me very well and I believed would write a strong LOR. During both of my open file interviews that letter was brought up multiple times in a very positive way. Anyone who can write you a letter that is professional and personal is a definite plus. It is exponentially better than the generic "person-x was in my Orgo class and got an A, they would make a good physician" letter.