I know engineering has long been dismissed as a min/max profession, so I'm not surprised nobody has mentioned the PTR changes to engineering but the
Hyperspeed Accelerators are (potentially) getting a huge buff in 3.0.8 and at least a minor one. The patch notes themselves say increasing the duration from 8 seconds to 10 seconds, but in game the cooldown has also been reduced to one minute instead of two. Since it's not in the notes and the tooltip still says 2 mins it may very well be a mistake, but I have a feeling it's not. I even brought some maths to back that up.
10 sec duration w/ 2 min CD gives us 340 * 10 / 120 = 28.33 effective HR (~28 item points worth), which isn't better than hit or exp if not capped and may or may not be better than 44 AP if you are.
Take the LW wrist enchants for example, 114AP is 57 item points worth, obviously much better than the other wrist options.
If the current PTR changes stick though and the CD is reduced to one minute you're looking at 340 * 10 / 60 = 56.66 HR (~57 item points worth) which puts it on par with the LWing enchant item point wise and unless your hit EP is way overblown from being way below the cap, would become the best wrist enchant by far. Even if hit was rated at 4EP and haste at 1.5EP, the accelerators would still be marginally better. Since most other professions personal enchants are in the ~50-60 item point range, or 20-25 points over the comparable enchant, this puts engineering on equal ground with the other professions as far as its apparent intended value.
Add to that the fact that it's burst haste and the EP can be even higher. Still off GCD and does not trigger the mini trinket CD that prevents dual trinket usage, so you can trinket at the same time.
Would it be possible to get this added to the sim to evaluate how good (or bad) it possibly is.
Another (hopefully simple) sim request, could you have the simulator set the processing threads to below normal or idle priority so it doesn't bog down the PC any more than it has to.