Some five-head showers have a small pump that recirculates the warm water to reduce usage. A low-flow standard shower head is a must. Most new filtering heads remove chlorine with a KDF element and save water too. These have motion and humidity sensors to make sure that they do not run too long or too little. If you get up often at night, consider a model that also has a built-in night light.
Many new models are decorative and ornate.
One-piece models are most attractive. Pressure-assist designs provide a positive, quick flush, but are slightly noisier. My mother lives in an older house that has no insulation inside the walls. I believe there is a lot of cross bracing in the walls, too. All walls have many obstructions inside of them, which makes it difficult to eliminate voids.