My 190E 1990 has over 160K (miles), never had any tranny trouble, shifts smoothly...although it does have the "Mercedes feature" on the 1- 2 shift the first time I drive it in the morning.
Other than than, I would trust this car to just get and drive any time.
Only major problems have been the computer module needed to be replaced around 50K, rear sway bar replaced, water pump elbow connector replaced (broke in Christmas evening rush hour...only time it left me cold and stranded), and oil light seems to come on after about 3500 - 4000 miles after each oil change, so I just go ahead and do an oil service at that point anyway. (Obviously using oil somewhere, but doesn't have a telltale smoke trail...compression and other checks have come back clear)..done this from the first day I owned it. (29K)
In all, I hope to see another 100K plus!
'90 190E 2.6
'87 300TE (gone to car heaven)
'84 190D (passed along...still in the family and used on a daily basis)