Very well made and a great Kohler product.  The dual-flush feature works perfectly so far and amazed at how little water it uses compared to our 35 year old toilets.  The tank's flushing system has some amazing technology to it and it is not your typical hardware store flapper valve system.  Completes its flush in about 3-4 seconds and uses between 1.1 and 1.6 gallons per flush (gpf).  To me, it's worth 5 stars.