For me i used both, i have bitcoin for my investment and sometimes i used this for paying my bills because there is a rebates in every transaction i made then i have bank account for my savings that i want to earn some interest with it and also for my future.
were same i prefered to use bitcoin wallet and banks , because i use bitcoins to grow or to trade into another coin so that i can grow my coins fast if you say 5% or 10% a month thats okay i also use bitcoin wallet to pay my monthly bills where it has no hasle because here in my country we can pay bitcoin as a payment on our montly bill i also use bank account to withdraw my bitcoin and deposit into my bank 