Don't be fooled by the size of those jets! They pack a punch. The arms are like mine, minus the embossing on the lower arm. i was thinking that too about the model being near the bottom of the rung...the tip off is the racks and the silverware tray, but no worries it will still perform well. I wonder if this model will alternate arms like mine does.
As far as not having a water softener goes, as long as your water isn't really hard, there should not be an issue with performance as long as a good detergent is used. But getting back to the jet size, compared to what the jets are in the previous machine, yeah they are much smaller. Miele makes up for the that with a higher wash arm speed. Once the machine is hooked up you will see what I mean. I know with mine, I can throw things at it like crusty pots and pans, and they come out spotless.