It looks like a way to get a Venetian plaster look, but more resilient. I have looked at few websites, seems popular in Spain/Italy.
When you say you have been playing with samples, is that applying it to test areas in your bathroom or or looking at finished samples form the manufacturer?
Would building something out of Wedi panels as a base for the microcement work? I like the cement look and am hoping to find an alternative to the Wedi top panels.
If you have the time, a build thread with lots of photos would be much appreciated. ?