Gas or electric towel radiator?

I have gas central heating in the whole flat except the new bathroom which is only about 4 m2 and want to put a towel radiator in I've calculated about 500 Watts needed to warm the room up but can't decide whether to link it to the central heating or use an electrical one.

 

Dual fuel, runs off CH in winter and electricity during summer to dry your towels. A decent one will have built in thermostat/timer for the electric.