In a message to staff on his first day at the helm of RBS, which he spent at the bank's London office not the Gogarburn headquarters, Mr McEwan's praise rang more loudly than that of Chancellor George Osborne when Mr Hester's departure was announced in June.
Mr McEwan said: "Five years ago, Stephen Hester inherited a very different bank to the one we have today.
"The world was watching as we stood on the brink of collapse with no clear way forward. I want to say again that Stephen and his team have my deepest thanks and respect for the job they have done.
"We are now on a stable footing and this is a remarkable achievement that we must never undo."
The New Zealander who had headed RBS's retail business for barely a year before his appointment in August, has most recently outlined plans to cut 10% of UK branches and another 1400 jobs.
But yesterday he reassured staff that he wanted the bank to become a company "most importantly, filled with the pride of its people".
Mr McEwan said: "We know that sometimes we make it too hard for our customers to do business with us. My aim is to make RBS one of the easiest banks to do business with. The same is true when it comes to working here - we have too many processes that get in the way of people simply trying to do the right thing for the customer."
He said a strong home market was the priority and RBS was "an international bank because our customers trade globally", while the bank's primary goal of helping its customers succeed "includes an increase in lending".