Contemporary or traditional styled bathroom heated towel rails are ideal for the compact bathroom, however they are small and although good for warming towels they are not so good for heating your bathroom. They are available in different finishes such as: (white, chrome and anthracite)
Radiators, on the other hand, are very good at heating your bathroom but not so good for warming towels. Designer radiators come in different finishes (white, chrome and anthracite), however they are also available in panel & convector style and also traditional column styles enabling you to harmonise with your traditional bathroom.
Finally, you may choose underfloor heating (wet or electric). Clever thermostats enable this system to offer a consistent warm temperature within your bathroom. You may be best to consult your professional bathroom installer to discuss the option that is best for you?