"But this side are taking the game to levels not seen before."
McGeechan is well placed to assess the All Blacks and the enormity of the challenge in front of Gatland and his Lions.
The former Scottish centre is intrinsically linked with the Lions. He toured with the British and Irish Lions in both 1974 and 1977 as a player and was the Lions head coach in 1989, 1993, 1997 and 2009. He also coached the midweek side on the 2005 tour of New Zealand where the head coach was Sir Clive Woodward.
McGeechan was fulsome in his praise of the Steve Hansen-coached All Blacks.
"So where does this current class rank?" he asked Telegraph readers before answering his own questions. "You have to say first that the opposition is way behind. South Africa are struggling and Australia have definitely gone backwards in the last year. It is also a shame England do not face the All Blacks until 2018 because they are the second-ranked side and it would be fascinating to see how close they are.
"Is this New Zealand side the greatest side of all time?
"Next weekend they will probably break the record for most consecutive victories with 18, and, after watching their demolition of South Africa by 57-15, there is no doubt that we are seeing something very special.
"What has been particularly impressive about this side is that they have done all this with new players coming in. They lost some legends after the Rugby World Cup last year, but their game has just continued to evolve, mainly because, I think, head coach Steve Hansen has not imposed a pattern upon them.
Obviously there is a core group of players, led by captain Kieran Read, who have been there some time now, but what Hansen has done is allow the newcomers to add their strengths to the All Black game. It makes the team so enjoyable to watch because you are never quite sure how they are going to evolve in attack."
McGeechan offered Beauden Barrett as an example of his point.
"It is not a case of these players fitting in, rather it is the group that is already there reacting to the new qualities being introduced. And what that does is make the side harder to read for the opposition," he wrote.
"The two halfbacks, Aaron Smith and Beauden Barrett, are the best in the world for me. Barrett has made a huge difference since he came in at fly-half. His ability to create space and attack it is remarkable.
"And then you see how well T J Perenara played last weekend at scrum-half in Smith's absence and it highlights the depth they have as well as that ability to respond to a new player's presence.
"The try Perenara scored was quite outstanding, with some remarkable dexterity shown by the likes of Read, Israel Dagg and Dane Coles in the outside channel. But it was nothing to do with pattern or style of play. It was just good players in good positions producing good skills under pressure.
"And the key is that the All Blacks keep coming at you. Look at the number of times they score after the hooter has gone. There is simply no let-up.
"They have never scored enough. That has always been the case with New Zealand rugby, even since I played against them. To have even a sniff of beating them you have to understand that sort of mentality. It is what the British and Irish Lions are going to have to do next year."
McGeechan also used the column to note the recent comments of England coach Eddie Jones who claimed teams needed to stop trying to copy the All Blacks and should instead find alternate ways to beat them.
"When Eddie Jones says that England should not copy New Zealand, there is actually nothing to copy in terms of pattern. But there is one heck of a lot to copy in terms of the skills, both individually and collectively," he wrote.
"Super Rugby is New Zealand's base camp, from where they take players and make them into All Blacks. What they are looking for is players with that mindset to be really positive, as well as the skill-set to be able to implement that.
"The Aviva Premiership is England's base camp, and the simple truth is that week in and week out the players are not challenged in their skill-sets in the same way. There is much more pattern.
"In fairness, the referees in Super Rugby are actively encouraged to keep a high pace in the game, and that in turn speeds up the reactions of the players.
"The New Zealand players' awareness and understanding are so good. I remember watching them play England a few years ago and Dick Best, the former England coach, was sitting alongside me. "Count how much quicker the New Zealanders are in position than the English players," I said to him. It was a difference of three seconds.
"That was for two reasons. One, because they knew that those players already involved would do their jobs properly. And two, because they were able to recognise where the next threat could be.
"Thus they are able to accelerate the speed of their ruck ball through the phases, because they are in position so quickly each time.
"So often in the northern hemisphere you will see one quick ruck, then at the next ruck the scrum-half will be pointing at his forwards to get them into position, thus slowing the ball down. The All Blacks don't do that. They do not need any direction to be given. They know where to go next.
"Often in rugby, it is not what you do on the ball but what you do off it that is crucial. The All Blacks prove that time and time again. It is why they so often appear to have two extra players.
"Take someone like England's Billy Vunipola, who has been superb in the last year or so. He can off-load like Read, but can he do so as quickly? You want to use his obvious strengths as a powerful ball-carrier, but I would also want to encourage him to be a little sharper in everything he does, including his re-positioning, so that he has an even greater effect.
"But it is not just in attack that the All Blacks are superb (they have won every game in the Rugby Championship with a bonus point). They can control contact so well in defence, not just in the tackle but also in the second man going in to slow the ball down.
"They only conceded five tries in this season's Championship, with fewer than 12 missed tackles per match (South Africa missed 40 last weekend!).
"That is total accuracy and reliability in all areas."
