EON have an online tool that lets you enter your energy usage pattern and amounts, it then gives you a comparison of the relative costs/yr of the various options. Coming off E7 was slightly cheaper for us and we didn't have to worry about setting things to run overnight.
With having a large family it has always made sense for us to be on Economy 7 and use our appliances overnight - we do not have storage heaters. I gather Economy 7 is only worthwhile if the units used overnight are around 25% to 30% of the total so, as ours are borderline, we are thinking of going onto a single tariff. DD3 and the children , obviously, increase our usage quite considerably but look as though they will be moving out soon.
I would like to know whether the meters would need to be changed if we changed tariffs?
I would welcome losing the 'tyranny' of Economy 7.
Thanks for your help!! And, any suggestions of good and bad companies would be nice too!