How it works: At the press of a button, a nozzle extends and directs a stream of water upward. The water is heated inside the unit, either on demand or in a small tank. Depending on the model, you also get a warm-air dryer, a heated seat, a night light, a remote, and a nozzle that rinses itself.
What it needs: a cold-water connection – at the angle valve next to the toilet or, with a wall-hung toilet and a concealed tank, under the washbasin – and a power outlet near the toilet. That outlet is exactly what many German bathrooms lack. In that case, the electrician comes before the shower toilet does.
Two designs: The all-in-one unit is a complete toilet with the technology built into the ceramic. The electric seat brings the same technology to your existing toilet as a seat. The line between them is blurry – technically, an electric bidet seat is largely a shower toilet without the new ceramic.
When it's worth it: when a new toilet is due anyway, when you don't want anything visible at the seat, and when installation and a power connection fit your budget.
When it's probably not: in a rental, with a toilet that works perfectly well, or when there's no outlet within reach.