The GE/Jasco zwave plus devices have been announced, but are not yet available for sale. Their support has said they’ll probably be out in December 2016.
Leviton also has a line of zwave plus devices coming, but not yet available for order. Same with Enerwave and GoControl
Current Z wave plus switches that you can order in the US include Zooz, homeseer, and dragontech. It’s not uncommon for the smaller companies to bring a new technology to market first, as the older ones may want to sell down their existing stock first.
I would expect to see a lot more available in January 2017.
( By the way, “fifth GEN,” “series 500” and “zwave plus” all mean the same thing. The fifth generation of zwave uses the series 500 chip and is marketed under the catchier name of “zwave plus.” )
Also prices on Amazon are often a higher ( sometimes much higher if it’s a small company and the items are being offered on Amazon by a third-party) than prices at the specialty retailers, particularly if you are going to buy at least 6 and are looking for a bundle price. so definitely shop around. For example, last time I looked, the Homeseer switches cost almost double on Amazon compared to buying them from the Homeseer site.
Most people who have the homeseer switches seem to like them, but some people have reported that the double or triple tap processing is taking too long. It’s hard to tell whether that’s a local mesh issue or not.
The DragonTech pocket sockets seem to be good, but there have been some complaints of an unusually high number of defective units among the wall switches. (The wall switches and the pocket sockets are made by different companies, then rebranded.)
I haven’t seen any reviews one way or the other on the Zooz switches, they are very new.
So as always my recommendation is to only buy from places with a good returns policy.