How does bow haste work?

[fzzzt]

I just got my first weight-reduction (WR) quiver, thanks to a generous soul in SK. Does anyone know how bow haste works on P99? I didn't find anything in the wiki. Specifically:

• Zam says 1/3 of an item's WR is applied as bow haste. Does P99 do follow this, or anything at all?
• Do the arrows need to be in the quiver or does just having it in one's inventory work? What about if the quiver is empty but one still has arrows in other bags?
• Is this haste Ranger only or can other classes benefit from it?
• Are there any other quirks to be aware of?

I did some testing with my new quiver and it seemed like I got one extra shot with it in my inventory, top slot, full of arrows. I have a 43 delay bow and I got 7 shots with and 8 shots without the quiver, over 30 seconds. That might just be the timing of my button mashing, though...not a great sample.