(This was originally posted here in the Hunter forum.)
From what I've seen, although different speed bows can have the same DPS, slower bows will usually have a higher maximum damage.
To give you an example, take two weapons:-
The High Warlord's Street Sweeper, with a DPS of 55.9, damage range 129-195, attack speed 2.9.
The High Warlord's Recurve, with a DPS of 55.8, damage range 80-121, attack speed 1.8.
At first glance, you're possibly going to assume that all other things being equal, the Recurve will give you more damage. After all, more overall shots fired = more overall damage, right?
Out of these two weapons, for my spec, I chose the Street Sweeper, for two reasons.
The first reason is that out of the 129-195 damage range, the Street Sweeper will hypothetically average prolly 140-150 or so. (This isn't counting ap, of course) The catch here however is what happens with armor. If in PvP, you hit a Warrior with 50% damage mitigation, (for the sake of argument) that 150 damage becomes 75.
With the Recurve, you're probably averaging 100 damage per hit. Against our hypothetical Warrior with 50% damage mitigation, (probably a conservative estimate) that goes down to 50 damage, which translates to 25 less damage per hit than the Street Sweeper.
The reason why this is important is because:-
1. Often during kiting in pvp, you'll only get one shot off before having to move again...so you want that one shot to count as much as possible.
2. The Recurve's damage (and crit damage) range even with Aimed Shot and friends will therefore also be lower per hit as well, for the same cost in mana.
3. Your damage numbers with the Recurve will be more inconsistent, depending on the armor value of the target.
The other major reason why I chose the Street Sweeper is because even in pvp, if I can get my boar or another player to tank my target and thus stay at range, I like to have a nice, stable shot rotation...because inflicting the maximum possible amount of pain and suffering upon the Alliance is something I greatly enjoy. ;-)
What I mean by that is, when you fire a Steady Shot or one of your other mana shots, what will often happen is that an autoshot will fire immediately afterwards, which can get you another white crit immediately after the mana shot. With a 2.9 speed weapon, it's a lot easier to make sure that this happens, in order to maximise your damage output. With a 1.8 speed weapon, it becomes a lot more difficult to time each mana shot; you'll be button mashing in order to try and keep up, which will either mean you don't get an autoshot between mana shots at all, or you get more of them than you anticipated.
Thus, I'm finding a slow weapon to be better for both pvp and pve.