Fund managers and retail investors have given mixed responses to the appointment of Matt Comyn as the next chief executive of Commonwealth Bank.While investors differ on whether Comyn is the right person to address the bank's cultural problems, most said they were surprised by the board's "unanimous" decision to select an internal candidate.The chief executive of Falkiner Global Investors, James Falkiner, said he was sceptical about whether Comyn's appointment would deliver the organisational change required."You don't achieve cultural change by appointing internal candidates," he told Banking Day."Cultural change can take ten years or longer and it's quite difficult to implement in large organisations such as Australia's major banks."I'm sure Mr Comyn is a bright person and a capable executive but he is part of the existing culture."Mr Falkiner, a former bank analyst, said he was concerned that the erosion of public confidence in the bank triggered by the money laundering scandal had forced the board into making a relatively hurried decision."The new set of eyes really needs to be a clear set of eyes," he said.Sean Sequeira, chief investment officer at Alleron Investment Management, said he had not expected the bank to appoint an outsider to the top job."The retail banking operation, which Matt Comyn has been leading, has literally made the CBA one of the best performing banks in the world," Sequeira said."So, it suggests the bank would like to clean up the culture but not fundamentally uproot the whole business."Sequeira said he trusted the judgement of CBA chair Catherine Livingstone who had demonstrated a capacity to steer other companies through reputational challenges."I trust her judgement," he said. "But it's yet to be seen how they will address some of the issues they have."Sonja Davie, the Australian Shareholders Association's CBA monitor, said she had expected the board would appoint an outsider."I think I would have preferred an external candidate - not someone from overseas, but a local executive who could be seen to have a different approach and bring a different culture," Davie said."Apparently the board looked outside the organisation - you have to assume they know what they're doing."There is a bit of a question mark about how much Mr Comyn should have known about the problems with the intelligent ATMS and the bank's anti-money laundering procedures."