That gearing strategy was created with the old healing rotation and script. (Which would definitely explain why haste was valued so low.)
We completely redid the healing simulations. There is one script and one rotation right now: the “Starter” rotation and script that we are using to test the new simulations.
Here is a sim of your character with the new stuff:
http://www.askmrrobot.com/wow/simulator/report/2674174afdc742dfb16b8c5b90961fcb
The script/rotation are labeled “starter” right now because the new healing sims are still in testing and the rotation isn’t totally fleshed out, although it’s at least at a point where it gives results that look somewhat like what players would do in a raid.
And yeah… I feel like dark titan is sort of a “hidden” legendary that is actually ridiculously strong,