McGeechan rated the Autumn series in Britain, Ireland, France and Italy in his Sunday Telegraph column.
He ranked teams out of 10: England 8, Scotland 7, Ireland 8, Wales 6, France 9, New Zealand 8, South Africa 8, Australia 7.
"You cannot judge the All Blacks on the basis of an autumn campaign in which they were clearly running on fumes," he said.
"At their best, New Zealand still play a brand of rugby to which the rest can only aspire. Never out of a contest as they proved against Ireland and France."
McGeechan said Ireland and France had outgunned the All Blacks' front five, and that was a weakness.
"Brodie Retallick and Sam Whitelock are not young men anymore. Ian Foster has a lot of pressure on his shoulders. He also needs to settle on a first-choice balanced midfield," he said.
Beauden Barrett was the side's key player. His absence was felt in the Tests against Ireland and France, he said.
South Africa had the world's strongest pack, and he expected they would add more variety to their attacking game while they had 'incredible athletes' in their backs. Discipline on the field was a weakness, along with a disorganised domestic game, he said.
Australia had attacking potential and wonderful backs when they were all fit. They lacked depth, struggled in the set-piece and had a big difference between their first-choice players in the midfield and front row.
England had gone through an epiphany in style change and had blooded several young players. Its attacking game was a work in progress. There were issues in scrummaging and a lack of depth at tighthead.
Scotland had its strongest team for 15-20 years when all players were available and could score tries from set-piece plays. It was dangerous but needed more consistency. Lack of depth and discipline were concerns.
Ireland had no weaknesses, had an experienced pack with some new names making their mark. Kiwis James Lowe and Jamison Gibson-Park had helped Ireland play with more ambition, although a weakness was its reliance on the older Johnny Sexton.
Wales struggled with injuries and lacked consistency upfront but was developing strength in its midfield and, with players recovered, would be more of a force in the Six Nations. Lack of depth remained a concern.
France had pace, power and panache and had regained the ability to run in tries from anywhere. Its big ball-carrying pack was backed by the best inside back pair of Antoine Dupont and Romain Ntamack. Indiscipline could be their Achilles heel, he said.