I'll ride the MUP pretty routinely (the busy and only parallel road has a lousy shoulder and requires pretty aggressive VC with occasional turnouts)... but the weekends are a red flag for me. That was one of my first experiences, and periodically I'll make that mistake again and have to bail on the MUP part way through, but it's so atrociously crowded on Saturdays and Sundays (especially considering it allows very slow-speed automotive traffic to boot). It's a very wide MUP, but it's a huge hassle to ride down weekends... when group after group of cyclists, swerving (4) line up and block the entire operation as you're just trying to keep up a mediocre clip.