Okay, so, I will start this off by saying I'm not currently raiding even normals because most of my guild quit with MoP, so this is about raid finder stuff.
That said, I do still try to gear up as best I can from LFR. So I asked Mr. Robot what it thought my BiS pieces were from t15 LFR so I'd know what to spend my coins on, and I got a very strange result for the weapon.
These three weapons are listed in order from "best to worst" on its own list.
And when I hit the "Find best in slot upgrades" button, it told me that my best weapon choice would be Durumu's Baleful Gaze... or, its own third option.
So at first I figured it was doing it because of stat allocations and a red socket, but then I realized that Durumu's xbow is just plain worse than the other two. It has lower topend and worse agility, with its redeeming factor being a red socket... and I guess it has crit on it versus hit/exp/haste.
So what is it I'm missing here? Everything in my system is telling me to disregard that because, clearly, the one with higher agility and topend damage is the better choice. If the red socket was really that big a deal then wouldn't the 500 agi from my 2x upgraded RF Taoren be better than all 3?
I would bet that it favors Durumu's because the red socket means more AGI given that the bonuses are the same and the Long Bow has hit and exp and if those are wasted on your toon (you're capped already), then even with reforging some of the stat budget is wasted. I'd bet that Best In Slot is tuned to your character's overall stats whereas the BiS overall is Longbow since hit and exp are, in a vacuum, 'worth more' than crit or haste.
BiS is a concept that really has to account for things like caps - it might be that the strongest individual pieces make up a set that's actually suboptimal by doing things like putting you far over hardcaps, etc.
I guess I understand that, but I was under the impression that the topend of a weapon is just really important. Would it just be better to force it to build a set around the best weapon, or do you think taking the topend damage hit would work out better in the end?
For reference, I tried simming it on femaledwarf, and it did also report that Durumu's better... but I also may have screwed that up because I've never been fantastic at using sims.
Why would you care about topend? No, really, I don't get it. Average is same, so higher top means lower bottom...AND more RNG. It's only better if you're hoping for some lucky streak to get into top logs, but hoping for that from weapon damage is last thing you can do.
Voice has best Agi, but if you're using valor trinket, you might be way over hit cap already, so in that case Durumu gets better. You might notice that Askmrrobot has two options for comaring - "Absolute" and "Relative". Absolute considers only stat weights, and Relative takes your own hit/exp caps into account. That's why they can differ.
Viscoe, I'm from Ask Mr. Robot. Here's some more information on Absolute vs Relative ranking and how it affects the BiS lists (which previous posters already mentioned). You can lock in the bow if you want, and Mr. Robot will find a new set of gear around that. You can compare the score to his set and your locked set, and see how it differs. Maybe it's 5 points apart, maybe 5,000.
Notice that agi/stam distribution is equal across the board, except for VotQ, whose item budget swaps 80 stam with 80 agi, which is a pretty damn ideal tradeoff. That combined with an ideal socket/socket bonus (STL with it's baseline hit/exp + a blue socket, encouraging an agi/hit gem... ridiculousness). Secondary stats on it are not necessarily ideal, but those are usually of little importance when considering Agility's very high value and the possibility of reforging (esp when you can ditch the +hit valor trinket when you finally end up with Renataki/Juju), in addition to the fact that hunter secondary stat values are generally considered very close.