D9 Max has more power when vacuuming, that was important to me. I don't use it for mopping... I can't judge. Otherwise, I can't find fault with the robot, it vacuums all areas reliably and has a good "orientation" in my opinion. It obviously compensates for the side sensor by turning to cover all directions, only then does it move on. OK for me... maybe it takes longer compared to the D9 ? Can't be a huge difference...

Now the prices of the two robots seem to be similar, but the D9 Max has 1000 Pa more suction power, less noise and an anti-tangle design.

Attention the D9 Max is less powerful than the D9
D9max: more powerful in aspiration
But no side sensor for walls
:Clearly less intelligent
No pre-filter in the tank
Much more abrupt than the D9 (I have both)
In short, the D9 is better