Triples maximum current to 3A per channel. http://www.bit-tech.net/news/hardware/2014/05/06/scythe-kaze-master-flat-ii/1
The body of the original Kaze Master Flat was made entirely out of plastic. Even the sides and front. It looked and felt cheap and flimsy. This needs to be metal all the way around to get my money. I can't tell from the pictures.
Got the original Kaze Master over 5 years now and its still working perfectly. More power output in the new one is a neat feature, even I hadn't any problems of running more fans on single channel.