I bought the EF-X500 and really like it. I know it's pricey but not really when you compare it to what Nikon/Canon offer. Nikon's comparable flash is $600. The EF-X500 TTL is perfect, better than the Nissin i40. My biggest issue is that you need a 2nd EF-X500 to use off camera, or a cable. I tried the Cactus V6 II and couldn't get it to work.
That being said, I also have a Nissin i60 and air commander coming today. HSS should be available for that flash mid-January. I "think" you need to send it in for a firmware upgrade when the HSS becomes available, but it's a fast turn around and free, you just pay to ship to them. They kindly pay the return. I updated my i40 with them and it only took about a week. It now works with the XT2 (but no HSS with the i40 - TTL works fine).
http://www.nissindigital.com/distributors.html
For work (real estate photography), I like the Yongnuo IV's and transmitter. Works like a charm. No HSS or TTL though. Godox is also very good, again, all manual.