A few years back I decided to play with polyphasic sleeping. I gave up after two weeks, because I wasn't well rested enough to have access to my best cognitive output and it didn't seem to be getting better, but I'm pretty confident I could have sustained it at that level if I had wanted to. The remarkable thing was just how painless the entire process was.
Everything I've ever seen about adapting to polyphasic sleeping is that it's supposed to be hard and miserable. In particular, it's a will power intense process and it's difficult for people to wake up. Common advice is that you need someone there to wake you up — preferably someone that can be insistent even when you're a jerk at them and want to keep sleeping. When my friend tried to transition without someone to wake him up, he got an alarm that required him to shut if off by scanning a QR code he kept in the kitchen — only to wake up and find that his phone had been disassembled and he had no memory of doing it. I've read similar stories of other people doing the same thing. This was not my experience at all, and I can explain why.