Edit 10 Nov: Added Soulbinder paragon info. I have had limited time testing and things are still being fixed/changed so my opinion is not final. Overall my current opinion is that it adds nothing useful to the current PvE setups, effects are too niche or too minor to justify the shift. The loss of HR, NPNM is not worth it for damage and utility builds.
Edit 3 Oct: I've done multiple runs post TT rework and it's still a great daily, you should still use it in the same situations, but it is more important to hold back encounters and damaging sources so you can use them while daily is up to maximise damage. TT is still overall a significant source of your overall damage if you do it right (45-60% of outgoing damage from my parses)
Edit 30/9. Some of the build links were not working and now updated. If there is a clash, use the written version over the link.
This guide is a work in progress, initially a theorycrafting exercise but adding info as I become aware of it. There's a lot of testing and quantifying effects to be done and by no means can I claim I know everything. There's a bunch of bugs and possibly unintended mechanics for the class right now, as expected with anything at launch so the optimal playstyle may well change in the future.
The discussion, like most of my guides is based on practicality for PvE dungeons although I will mention applicability for PvP and other situations where warranted.