@Tiase - We actually have stat calculations coming sometime next week (that's the goal) for the simulator. We are taking a pretty robust approach to handle stats for Legion. And then for ranking gear, we'll be ranking the harder stuff (like trinkets and legendaries) from actual simulations. We're pretty excited about that, it will take gearing to a whole new level.
You can play with it right now on http://beta.askmrrobot.com - load a generic character and choose the 840 gear profile (instead of the PVP one). Then what I do, is on the setup page, I scroll past the gear and expand the 'stats' section. Then I add value to one stat, and take an equal amount away from another (to keep it realistic for that gear level). Then I simulate it and see how the damage changed. **The simulator is meant for Legion characters, so we have all Legion legendaries and gear modeled, but we do not have old warlords set bonuses or trinkets modeled. FYI.
Then next week we'll be able to run these sorts of things FOR you (instead of manual setups).
We have a ton of Demon Hunters playing on the simulator today, but it's still pretty new to a lot of people. So I wanted to share a crash-course video I made. It's all web-based and easy to use. You can change gear and artifact stuff just as easily as you do on the regular site, it's pretty handy. Hit me up if you have questions.