Hansen is amongst the best coaches the All Blacks have ever had. You could argue his record is second to none. His ability to keep on keeping on owes much to that Bear-with-a-Heart personality. He's a man who learns, adjusts, adapts. Players trust him, implicitly. He has strength. He commands.
The stand-out coach in world rugby - apart from Hansen - is another Kiwi, Joe Schmidt. That's who the All Blacks should be targeting, somehow, without offending his Irish paymasters.
Ian Foster has done nothing, in terms of winning titles, to suggest he is head coach material. Far from it, actually. He has been a brilliant foil to Hansen, but there is a huge difference between head and assistant coaches.
Foster is Steve Hansen-lite. Personality wise, he is extremely well liked. I'm told that important tactical changes to the All Blacks' game can be credited to Foster, and like Hansen he may well be able to improve with age and experience. But there comes a time with all dynasties when in-breeding becomes dangerous. The Crusaders are a prime example of that.
Schmidt - whose achievements include plotting Ireland's first win over the All Blacks - has a priceless world view, a reputation as a master tactician and by far the greatest potential to take the All Blacks forward in a significant leap. The All Blacks should always be looking to raise their game. Schmidt's fastidiousness, his ability to improve players, is already legendary through what he has achieved in Europe and particularly Ireland.
The new All Blacks assistant coach will bring in new ideas of course. But no New Zealand-domiciled coach gets close to matching what former Blues assistant Schmidt has achieved and experienced in Europe.
Interviewed on Newstalk ZB, Wayne Smith revealed to sports host Tony Veitch his frustration with those who criticise Foster's record at the Chiefs. But Smith is on thin ground there - Foster's failure was put in context by the success which immediately followed his departure.
Finally, Smith deserves an avalanche of accolades for his immense contribution to New Zealand rugby's success, and the classy manner in which he achieved that.
He is often called the Professor, for his rugby intelligence, but a key to his success is a genuinely selfless attitude. It was always about improving the players, the team, with Smith. He won trust, confidence.
He can be a prickly character - ask some media people on that score. Yet there is a humility which extends to questioning his own position as All Black coach in 2001, which helped cost him the job.
Even yesterday, he questioned his right to promote Foster as the next All Blacks coach. He has every right - I just happen to believe he's not right.
Schmidt has the greatest potential to take the All Blacks forward. If Foster takes over, they will be lucky to stand still.