For those who are doing the math...
1. Steady Shot is affected by haste. Meaning with a 15% quiver it has a 1.3 cast time and with a 15% quiver and Serpents Swiftness it's down to 1.09. Note that haste is multiplicative, not additive (15% faster means attack speed / 1.15, if you have serpent's swiftness it's attack speed / 1.15 / 1.2, or attack speed / 1.38).
2. In order to keep from clipping auto shots with steady shot, you need a 1.59 attack speed if BM, or a 1.8 attack speed if MM/SV, since auto-shot has a cast time of 0.5 seconds at the end of the casting period. This is assuming no lag and no human error. Adjust times as you need to. Converts to a 2.19+ (2.2+) weapon attack speed for BM and a 2.07+ (2.1+) weapon attack speed for SV*
3. There is a 1.5 second GCD that is NOT affected by haste, and does not affect auto-shot. This makes the Steady Shot only able to fire in 1.5 second intervals, even though you could fire one off in 1.09 seconds if specced BM.
3. In order to throw arcane shot into the rotation without clipping the second-next auto-shot (since it will delay the steady shot rotation by 1.5 seconds) you need a 2.3 attack speed when BM or 2.4 attack speed when MM/SV specced. This means a 3.174 base weapon attack speed for BM (no weapons that slow in game) or 2.76 base weapon attack speed for MM/SV (or 2.8+ attack speed).
4. In order to throw in multi-shot, you then need a 2.5 attack speed, so you can throw it in AFTER the GCD is up and still not clip auto-shot. That means 2.875 for MM/SV (not gonna count BM because it can't even fit arcane shot in), or a 2.9+ attack speed. Note that this does not factor in a steady-arcane-auto-steady-multi-auto rotation, but using arcane or multi shot on alternate cycles.
5. In order to do the rotation mentioned in 4, you would need a 2.65 attack speed, or 3.04 base weapon attack speed. In other words, you need the gladiator's heavy crossbow, the only weapon with a 3.1 attack speed.
As seen above, haste lowers the effectiveness of the shot rotations, which are largely based on the GCD and not clipping auto-shots, rather than on firing as fast as you can. So if you're attack speed is 0.9 without RF on, you wont have time to do any of the above shots except maybe arcane shot. Firing even multi would clip auto-shots.
Also, I did the math in another thread, if there's delay between steady and auto-shot (i.e. if you have a 2.2 attack speed as BM there would be 0.61 seconds when you're not working on a shot) there is minimal difference in overall DPS, if any.
So for a BM Steady/Auto you need a 2.2+ bow.
For an MM/SV Steady/Auto you need a 2.1+ bow.
For an MM/SV to add in arcane you need a 2.8+ bow.
For an MM/SV to add in multishot you need a 2.9+ bow.
For an MM/SV to have a simple steady cycle between a multi and an arcane cycle, you need the Gladiator's Heavy Crossbow.
*If you want to see my time tables I have them, but left them out for convenience.