A new personal banking survey by consumer group Choice has highlighted the yawning gulf in service levels between the big four banks and the mutual societies.

Out of the 14 institutions in the survey, NAB was the lowest-ranked overall, followed by CBA, Westpac and ANZ. The banks performed relatively poorly across a wide range of criteria including interest rates, fees, customer service and product range.

Australia's largest mutual, CUA, came out on top with an overall satisfaction rating of 84%. CUA scored particularly well in customer service, fees and product range but relatively poorly on ease of ATM access.

In the home loan satisfaction rankings, the big banks again fared poorly. Customers were particularly dissatisfied with the banks' tardiness in passing on RBA interest rate cuts.

Despite the gloomy results for banks, the survey found that many customers were unwilling to make a change. Of the respondents dissatisfied but unlikely to switch, 52% said it was "too difficult" or required "too much effort", 24% said there was "no point" because all financial institutions were "the same" and 7% said it was "too expensive" as they were locked into a fixed rate mortgage.