The first thing to do is to check the prices of the new providers, they
should be price cap rates but the Utilita contract may be different.
Service wise, I have no experience of either Utilita or Energy Billing
but if you start with the premise that all suppliers are equally poor
you can only not be disappointed.
Changing suppliers is not something to be entered into lightly these
days unless there are compelling reasons for doing so, e.g high price,
especially when moving into a new property, there are enough things to
go wrong on COT without adding another layer of complexity.
Good luck with the move!