[mickey.1430]

First of all, the tranny is sealed but not hermetically sealed. There is a clip on the tranny fluid dip stick tube which is broken upon removal: big deal. One has to purchase the dip stick to check the fluid level. It can and has been changed. Suggested numbers are in the 60k to 100k interval.
Two, the young'ens believe in the party line. That's OK because we have heritics who know better. For example, when inquiring about the recommended change interval for the tranny I was told that MB instructed the techs to change at 100k whereas a factory rep, yes a rep, suggested 60k for extended life, and some techs use 30k for themselves. I think 60k-75k is probably a save interval for piece of mind.
Three: As for 10k-13k oil change intervals, that is not a problem. The sump has twice the capacity of a traditional engine, so in terms of diluted junk, you are only doing 6k intervals which is only twice as long as the old 3k rule-of-thumb. With tighter manufacturing tolerances and great oil, that is no big deal. I know because I have my oil tested and they always tell me to run it longer.
Four: The odd thing is that the tranny has the same oil quality sensor as the engine but nobody seems to know what the readout numbers mean. The adaptive program uses the readout but in an unknown manner so I am not sure what resetting does after a change.
Five: tell the SA to keep speaking the part line but have her read some of the posts on this site, Mercedes shop and others.