I am very familiar with Canature and I have been to their manufacturing facility in China. They make some great stuff, but there valves do not compare to a Fleck or Clack valve. If he said he was going to get you a Clack valve, or if his website or literature showed you a Clack valve, demand he remove the Cantaure valve and reinstall a new valve. The Canature valves are the lowest cost units we can buy that maintain some quality standards, but I certtainly would not compare it to Fleck or Clack. Also make sure he did not use the Canature bottom screen, these have yet to pass even our simplest quality tests. The good thing is the valves are basically interchangable, the bad thing is, he is unlikely to change the valve. You got yourself a problem on this one.
Of course he will claim it is as good, they have a longer waranty etc. A hyndai has a longer warranty than a BMW, it does not mean the Hyuindai is better. How much did he charge you? I have a major problem with dealers selling these units for the same price as they would sell a top tier brand, it is only adding $50 to their total profit margin, not worth it to most of the more experienced and knowledgable dealers.