I have an Autoprop on my C30 and love it. One peculiarity with the Autoprop is that when sailing you should leave the transmission in forward not reverse like the transmission manual says. This is because when the Autoprop freewheels it spins the shaft in the opposite direction of when it is driven. This is very handy because you do not need to mess with the shifter to shut down or start the engine when in motion.
It has just a bit of prop walk when at dead idle but if you rev up at all it will back straight, right or left. I found that it makes a significant reduction in drag when I forgot to put the trans in gear during one race. I could not figure out why one of the "slow boats" was hanging with me upwind in a race and then I heard the prop spinning. After dropping into gear, I was a 1/4 mile ahead at the next cross.
One of the things that I like the best is that the prop has very little power at idle. When coming into my slip, I drop into reverse when I am 1.5 boat-lengths out. It just gradually slows down. When I want to stop, I just rev a bit and it stops quickly.
The prop is very powerful and can bring me to a full stop from hull speed in just over 1 boat-length.
I have never sailed with a folding prop so cannot compare them. I have had some friends say that they had difficulty getting their folding prop to open in reverse when moving forward.