Hi there,
I live in a two bed bungalow and I would choose free gas over esb. My gas comes in at 160 every two months and my esb would only be about 70 every two months, this depends though, i dont have a dryer or a dishwasher and i believe these items to make a huge difference to your ESB bill. I also very rarely use my imertion to heat water as my heating is on a timer and provides all the hot water we would need.
The Gas prices also go up alot more frequently than the ESB. Given the choice i would definatley rather have my heating especially where young children or elderly people are concerned.
You can always get a coin meter for the ESB where you pay as you go, i think they only do this in special circumstances now though.
Hope this was of some help.