I do this, mainly to collect the Avios and get upgrade vouchers for BA, but have a direct debit that automatically takes the balance from my current account on a monthly basis. Given the dreadful interest rates on current accounts there's not a huge value in having the money for 7 weeks or whatever, but it does provide a level of protection by using your credit card.
The only challenge I have is a lot of places (more up north I've noticed) dont take AMEX and so I need to have a separate Mastercard for those circumstances.