bit of work
I would guess there's a bit more work than just a drain, effectively the whole room becomes like a shower tray & has to be sealed up properly? (as well as having the slope on the floor).
Also, would there not need to be a dry staging area? where are you going to put the towels? how do you transition from a wet room to a dry bedroom?
Have to admit, looks good, but would take up more room than a traditional en-suite/bathroom by my reckoning. Some of the bathroom supplies stores might be able to give you more info, even some design consultancy?