I had this faucet installed in my newly constructed home one year ago.  In the past year the head has had to be replaced 6 TIMES because the boost button gets stuck in. it works anywhere from 1 day to two weeks before sticking.   The only reason I am giving it two stars instead of one is the fact that Kohler customer service replaced it so many times without question.  I was told they know this faucet has and issue with the boost button and are working on fixing it.