I voted with my feet, sort of.
My Yugo underfolder was sold. It locked up firmly and the paracord I put around the left arm of the stock made it not uncomfortable to shoot. The folding stock was angled more horizontal than some U/F guns, so I could get a good sight picture.
Come to think of it, I sold that before I grew my beard. The beard might not have played well with that underfolding stock. I suspect I would have found new and interesting ways to remove beard hairs...
But my new Arsenal folds to the left and is a solid stock that solidly locks up in the solidly open position. Really, it is so solid that I have to work hard at unlatching it. It is just right and I recommend that design.
Bart Noir