Seeing as somebody else brought this thread back to life, I will go ahead and add my comment.
I have only had my Toto CST454CEFG (Drake II, ADA, 1.28gpf, elongated, CEFIONTECT) since just after the first of the year, so can't speak for longevity, but the only time I have had to pull out the plunger was when the offering to the porcelain god was beyond imagination. And for cleaning, I just use dish soap and a toilet brush once a week, and most of the time it probably didn't even need even that (I do have water issues, so I am trying to avoid that from getting a foothold here).