In general, the Masters in Management is for recent college grads (people with 0 - 2 years of post-undergrad experience), vs. the MBA which is usually for people with 3- 5 years of experience.
They are usually 1 year vs. 2 years.
Think of it as "a way to get the equivalence of doing a business major, for people who did NOT major in business and now regret it."
The positions you get after an MiM are far lower-level than the MBA jobs (which makes sense, since it's a younger / less-experienced crowd). So, e.g., if someone were to pursue management consulting, the post-MBA title would be "Associate" but the post-MiM title would probably be Analyst.....or some hybrid role that is a bit above pure entry-level but not MBA level.
As Concordia mentioned, the career services offices should have plenty of stats about career placement.
If you get the MiM, you may realize down the road that you don't even need an MBA (as many people who did business in undergrad eventually find out).