Digs map was most enjoyable for me. I was afraid of nasty manipulations of teleporter exit angles, but it was only for Escher looks.
Doomer. Enjoyable, though curved staircases was too thin imho.
Shamblernaut. Well it looked Escher alright. Downside is that I had no idea what am I doing.
For me it was hard to understand because there was no clear goal and thus no way of telling if I'm progressing towards it or in a limbo between 2 teleporters.
At one point I thought I figured it out and tried to use audible teles, thinking it is the right ones and all other is silent.
Finished the level by accident.
Didn't play Cocerello's map because of quoth 8( sorry.
3 hard demos here
https://drive.google.com/open?id=0B3li06myS1r1bmwySmlpcXVQR3c