Drago's Flatbow or Urgoz's Longow?

In any barrage build, you will be more efficient using a vampiric weapon. It's not necessarily a bad idea to have a sundering long/flatbow, but it's really best to be used only as a secondary backup bow that is switched to when you are taking damage while attacking little or for simply when you are not attacking at all. A general rule of thumb when choosing a bow for a barrage build is:

If you will be under the effect of Favorable Winds, but no IAS:
Use a Flatbow

If you are under the effects of an IAS:
Use a hornbow (an IAS will give a greater net increase in attack speed to a hornbow, thus giving it better dps than other options)

If you are not using an IAS and are not under the effects of Fav. Winds:
Use a Long/Recurve bow or even better, adjust your build so that you will have FW and/or an IAS with you. I run barrage build with some interupts, and needling to finish off, still i prefer a vamp recurve bow, even with favorable wind in action. I will be more certain i can interupt the faster activating skills from a distance. so when in shortbow range it still takes 0.44 seconds for an arrow to arrive, in combination with the activation time, your response time and the internet time it will be near impossible to interupt 1 second skills, for a recurve bow u have a quarter of a second less time lost on flight.

But its just personal peference, I can only agree to that, a flatbow clearly outperforms ion damage output on stationary targets.

I run barrage build with some interupts, and needling to finish off, still i prefer a vamp recurve bow, even with favorable wind in action. I will be more certain i can interupt the faster activating skills from a distance. so when in shortbow range it still takes 0.44 seconds for an arrow to arrive, in combination with the activation time, your response time and the internet time it will be near impossible to interupt 1 second skills, for a recurve bow u have a quarter of a second less time lost on flight.

But its just personal peference, I can only agree to that, a flatbow clearly outperforms ion damage output on stationary targets. Flatbow users generally use either FW or RtW, so the arc is even smaller than a recurve bow's without FW/RtW so it's not a problem for interrupting.

Note: in a shortbow range, the arrow takes 0.59 secs to hit the target with a shortbow, and 0.40 with a recurve bow (http://gw.gamewikis.org/wiki/Bow#Bow_Classes). The key for interrupting skills with a fast casting time anyway is the anticipation. If you wait for your opponent to cast it, then click your interrupt, you're likely to fail. Use the interrupt before he starts casting the skill, because you know/feel he's going to use it, having the recharge time of the skill he's going to use in mind, or knowing the typical skill chaining of his build. Try to catch Willa's Orizon of Healing as soon as he cast it for example: even if you stand next to him, you won't succeed. Count how long before he uses it again instead, and the next time distract before he starts casting it and you'll catch it.