Alvizzei, on October 22 2014 - 12:24 AM, said:
please enlighten me why most pilot choose vulcan_ i can't seem to understand how a weapon w/ long fire animation & high heat charge be in favor over assault rifle_
is it because it's the "D" _

It depends on the map and playstyle. For instance, I run Vulcan on my Assault, but I only run assault in extremely team based matches (TPG, and TPG scrims/practice), and I only run it on Origin. This works very well because almost all MA engagements on Origin are close range, where the DPS on the vulcan is simply incredible. I don't use vulcan on any other mech, except occasionally to mess around in grenadier, where its tankiness/ability turns it into a 2 second mech shredder.
On the other end of the spectrum, I run AR on my berserker (mostly) because I only ever play berserker on Last Eco (and occasionally to mess around on other maps, but in that event I'm putting SMC on it), and last eco is a very open map, with a lot of potential for baiting opponents and then using the backward jump on the zerker to get out to long-mid range while keeping my opponent in the open and in the crosshairs.
Now, if I were to play either of those mechs on say, Uptown, Prosk, or Wreckage, I would almost always keep the SMC, because those maps contain a variety of common engagement distances, and my playstyle switches up for those maps.
This all being said, I am unlikely to be the best person to explain this, as I am not a fan of the berserker, and only rarely enjoy my assault.