Walk-in showers - with  no door - are on the popularity hot-list, for sure!  Up-side: very easy to get in and out; adds spa-like open-air feel to room; can be quite large; can be done with no glass to keep clean.  Down-side: takes more space - will not fit in smaller rooms; can be uncomfortably cold and drafty; no-glass versions can feel too enclosed, cave-like.

The best walk-ins are large enough to be comfortable without glass walls, are placed in larger bathrooms with well-managed heat and air-flow, and use dropped floor-joist sub-structure to eliminate curb.

Walls and shower heads must be placed to contain water spray.  Be sure to run large enough water supply lines to serve multiple or over-sized sprays/water jets.