I ride on a very nice MUP much of the time, but this time of the year, it can be very dicey. There are quite a few homeless people with their bikes and shopping carts and they wear dark clothing with no reflectivity and never have lights. When it is dark and raining, which is all the time here, it can be super hard to see them on that dark MUP. I have almost hit one on more than one occasion. They are just so hard to pick out of the blackness. Also, those ninja people or whatever we are supposed to call them, the "cyclists" with no lights or reflectors and dark clothes, they sometimes show up, too.
So, overall, a very nice path, but not without its risks. Really have to have your eyes peeled at all times.