Replacing two toilets and we definitely want dual flush. After some research I was set on the toto, but our local supplier has a kohler line called Sterling with a couple of dual flush options (Karsten and Rockton). They are about $100 cheaper. I've seen some negative posts about Kohler, but no mention of Sterling line or these particular models. I really like the look of the Toto Aquiia - but price and function are more important. Any advice?