I've ridden on two sets of MUPs extensively. I used to commute on the GW Parkway MUP in the 1970s, Alexandria to Georgetown. I still ride that sometimes. Nightmare on weekends. Highly mixed, random behavior. Most seem to understand how to work with others, but many don't, and that greatly cuts the safe speed. Still lots of weirdness on this system, including quite demanding drops towards Mt. Vernon, wet boards, plenty of crossings, and needless wandering of the path for some kind of misguided desire to make things interesting. Not that I can't ride it - I've done the whole thing on tandem many times.

I've also ridden the Maryville, TN system a bunch. Seems very typical. Blind corners, bumps, needless curves and hazards, incoherent users.

These systems work for slow speed recreational users. They may work somewhat for commuters in off hours. They simply don't work for actually using a bicycle to get places safely and quickly.

The need to blast around blind turns isn't the problem. The blind turns are the problem. A path for vehicles should have a great sight line to allow efficient use, not blind spots and other BS.

This is, of course, from the perspective of someone with lots of miles on roads, interested in riding at typical bicycle speeds (for performance road riders) averaging over 15 mph, often quite a bit more than 15 mph. The MUPs I've seen don't have sight lines, surfaces, camber, or anything designed to allow efficient road type cycling.

Of course slower riders are going to have a much different experience. On the other hand, I've seen slower riders picking up their teeth. The typical MUP mix when use level goes up creates unnecessary hazards. This is pretty well worked out.

And isn't misinformation, as suggested above.

I've only had that GW MUP go where I wanted.

None of the MUPs I've been on is at all suited for riding at my typical speeds, even if assured that no other traffic is present and that I could blow all the stops etc. They're tiny. Even compared to the smallest county road.