It depends whether you are the type of person who 'has' to spend all the money in their current account.
If not, it can work well to just keep it all together. We have the Santander 123 account and use it as a combined current and savings account.
It pays cashback on bills which will outweigh the £5 monthly fee for most people unless their bills are much smaller than average - we get around £4.50 but our bills are low - band A council tax, under £20 pm on mobile phones, no pay TV.
But it then pays 1.5% interest on up to £20k so we just keep most of our money in there and let it run itself. We actually do just about all our spending on a cashback credit card, which is then paid out of the account like any other bill.
So once the money in the account covers day to day and irregular spending like holidays, insurances, white goods replacement etc you don't really have to think about what the account is doing, whether there is a risk of overdrawn etc, and you get what is currently a market leading interest rate on all your savings and current account balance too.
We do have other savings that are less easily accessible, but this works for us.