For some reason, the C-Class MB's have had far fewer transmission issues than the other models. The ML's and R's seem to have more problems, IMHO.

Just tell your SA that the transmission doesn't seem to be shifting as smoothly as it should, and let him/her worry about it. The diagnostic process isn't all that complicated. They'll start by checking the basics (ATF level and condition, fault codes, etc. ) and proceed accordingly. The majority of shift quality issues are solved by updating the software in the engine and transmission. Sometimes the valve body needs to be replaced with an updated version. Now and then, the transmission needs to be replaced. If your car needs more than a software update, your dealer will need to obtain pre-authorization from MBUSA. Yes, you heard right, pre-authorization! . Since there are only a handful of factory-approved repairs for the 722.9, MB wants to be "kept in the loop", to help control warranty costs.

In your case, it sounds like the new software will take care of your problem, but there's a chance you'll need a new valve body. If this is the case, you'll get the fluid changed, but not the filter, MB Warranty simply won't pay for it. I know it sounds ridiculous, but that's the way it is.

Let us know how things work out.