I've had a 97 E420 for one year. The basic maintenance is really easy if you worked on other cars. Here is my experience..,
--The oil and filter can be done from the top of the car, if you use a TOPsider or similiar oil extractor. This is the easiest to do.
http://www.evozine.com/benz/oil.ext2.jpg
--The spark plugs are all pretty accessible with standard tools, just remove the black engine covering, valve covers and coil pack(s).
--The brakes are no different than other brake job, pretty easy
--Shocks are also easy to do...,
--The only hard item so far was the replacement of the headlight lenses. I only purchased a portion of the headlight assembly, which caused delays. If you do yours, purchase the entire headlight assembly, which makes it a simply one hour job,.
good car choice....
http://www.evozine.com/benz/