My rough downshifts are always when slowing down moderately. If I am accelerating and drop 5 to 4 then it's a fairly normal shift.
The thing is the car didn't used to do that until it reached about 80000km. The dealer of course said they couldn't reproduce the problem. My mechanic friend thinks the upcoming tranny fluid flush (due to be done at 120000km) should make things smoother. We shall see. It hasn't gotten worse - I've been driving with this symptom for a year.
According to what I have read the 7GTronic and the Plus variant can downshift up to 2 gears at once. In other words 6 to 4 or 5 to 3 are possible; it does not skip more than 2 gears though.
I recommend when you go to the dealer to demand doing a test drive with a mechanic or shop foreman in the car with you.
Interesting, I swear I've seen the gears on my car drop from gear 7 to 3 before in a single go.
I went to the MB dealer this week. They were very nice about the situation especially considering I didn't buy it from MB. The mechanic came for a test drive with me free of charge. He acknowledged that the vehicle has abnormal downshifts during acceleration. Based on the drive he said he doesn't think there is anything mechanically wrong as there is no grinding or clanking noises. However, it definetly should be much smoother. He seemed to think it was more software related or maybe low fluid level. I am going in for diagnostic testing on Tuesday where they will scan the computer, update the software if there are updates, a hard reset on adaptations (he said the key + pedal method to reset adaptations normally doesn't work all that well) and check the fluid level for $150.
I will post an update once MB has a proper diagnoses. They told me a tranny fluid change is $550 CAD. I'd hate to see what the rebuild cost is.