It is ideal under decorative ceramic tile that will hold the heat. Since this does not provide instant heat, consider putting it on a timer. Turn it on only during high usage times in the morning and evening. If you have ever used a towel warmer after bathing in a hotel, you know how great it feels. Using one lets you set the bathroom air temperature lower to save overall.
Most people add a whirlpool or hydro-massaging, multihead shower when remodeling.
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.