The differences between openers are forgivable in a long run; tens of potency lost over ~30 seconds, while tragic, is swimming in a sea of several thousand in the same timeframe (not even counting autoattacks). And in a short run, you can usually try your options out. In the future I hope to put together some charts to really explore these options, but that's not even on the horizon right now.

In tonight's edit (so... much... testing...), I will be swapping Blood for Blood into an earlier slot to alleviate That Thing: holding the 5th Mirage Dive for too long. It's possible to manage, but I think just one more GCD of slack makes it far less risky, plus I'm sure most of us are chomping at the bit to actually get to LotD by that point. It will perhaps be a weaker opener on paper, but technically it's more aggressive with the stronger cooldown, so without proving it, I think it's hardly even a tradeoff; a Mirage Dive and/or a delayed LotD window is the worse loss by far.

In retrospect, I should have noticed that 60s and 80s is more than 15s difference, but on patch day I was excited by the Mirage Dive change and eager to get straight to the jumps.