Of Haste And Haste Brackets.

Or Why You Shouldn't Blindly Stack Haste.

You might've heard of me (or someone else!) mentioning Haste Brackets before and wondered, Why, what's a Haste Bracket, and why'd it matter (for me)?
Well, wonder no more, for I shall explain exactly why it is of critical importance for the success of your raiding ventures to be aware of those, and how they're aiding you in performing better!

As they would say, a picture's worth a thousand words:

(Picture not [entirely] to scale. Only for illustrative purposes. Haste Ratings valid for 3.7 speed weapons only.)

As you can see, each discrete Haste Bracket is the lowest amount of Haste Rating possible where you're still able to hit a target X times (5, 6 or 7 basically) within a 15-second* time frame. This is also the amount of haste we're aiming for, as being within a Haste Bracket means that we're delaying our last hit for as long as we possibly can, without exceeding our 15-second* time frame, as anything outside of it would make that hit ineligible for SoV5-upkeep, forcing us to spend our prior one on it instead.
*We're erring on the side of caution however and will, for all our intents and purposes, consider 14.8 seconds to be our target instead. This is to give us a small leeway to work with and ensure we're not screwing up our SoV5 upeek due to perhaps, the server hiccuping, or something. This also means that, for our Zeroth Bracket we'd actually be using 30-60 Rating to ensure we're hitting our 14.8 seconds. (Exactly 0 haste would make us hit every 2.99 seconds w/ a 3.7 weapon, which would result into a 14.95 bracket. Which is far too close for comfort.)

As we can now see, hitting your Bracket is of utmost importance. There's nothing worse than being just shy of your Bracket - it'd make SoV5 upkeep a nightmare! (You'd be forced to do it on like, 12.5s elapsed instead of 14.5s, with more than 2s of duration left on it, as your next white would be past the magic 15 seconds.)
While overkilling on Haste Rating isn't as dramatic as compared to underhitting it is still to be avoided as each point of Rating, past your desired grace-window will shorten your upeek window by a few milliseconds, and thus make SoV5-upkeep harder.