Since my initial review 18 months ago, I've covered 20,000 miles on these tyres on a mix of UK country roads and motorways.
3 tyres are at 4mm tread depth and the one remaining has 3.5mm. Therefore I would say that considering these tyres are designed to be "safe when worn" (https://www.michelin.co.uk/auto/home-auto/long-lasting-performances), I will replace them at around the 2mm mark, which means cosnidering they were 7mm when new they can be considered as about 60-70% worn - Hence I can expect a total lifespan of just under 30,000 miles from them. I consider this outstanding when most other tyres struggle to last much more than half this - which means that Michelin's argument that they are not expensive if used until actually worn is correct, although the initial purchase price does hurt at the time!!
There have been a few times during this time that I've had to brake hard and I've yet to activate the car's ABS system - So the grip levels are good enough for me and my eco-driving style for sure! My only criticism of these tyres is they are not great on icy roads - vastly better than other cars I've driven on the same roads on the same days fitted with Chinese summer tyres mind, but you still have to be careful and take it easy. The CrossClimate2 appears to rate much better in this respect, so there is no question of anything else replacing these.
In conclusion, Michelin are miles ahead of the game with these tyres and they are worth every penny of their price. Buy with confidence.