I use both, the ceramic heat emitters are good for keeping the tank warm, and the spotlights for providing a warmer basking spot.
Why on earth did they make someone from the greens the minister of energy conservation, all they'll do is whinge and grizzle and say 'don't dam that river', 'don't burn that coal', 'don't put turbines on that hill as it is visual pollution for the 3 residents that live 20km across the valley' and never offer any realistic solutions. Electricity has to come from somewhere!