I just ordered the RX200. I have read quite a bit about it and most are very pleased. I think the TC learning curve has caught a few users, but you have been running TC long enough you won't have any problems. I am starting my stockpile, and a triple 18650 looked like it would be handy at times.
I have not had an iStick since the 40Watt TC, but I personally have had great luck with them. I have thought about snatching up a few iStick 60W to add to my stockpile.
I don't know anything about the Herakles Plus. I do like the way it works, and I had great luck with the Herakles Ni200 (not plus) coils in my Saucecode.