Can you explain why spec into pull for melee drell? Why barrier bonus over double charge? The way I played mine relied heavily on the extra invul frames and additional stun proc I'd sometimes get from the double charge (I'm not saying I was doing it right, it just seemed useful). And I'm surprised by the adrenaline mod, isn't it fast enough already? I always played him with cyclonic IV which kind of offsets the bonus you'de get from full barier regen on charge, but can do it twice instead. And I was using inc ammo over dist, any reason for dist.?
I spec into pull just because I kinda like that power and launching a pulled enemy into space via BC or heavy melee is amusing. You can totally leave it out and max passives.
There is no real advantage of bonus power charge the way I play it. I have falcon for stagger, which is very handy. Since I'll melee after a charge, I want max barrier. My cooldowns are fairly low anyway that I can charge almost immediately after a charge > melee > shoot sequence (which will keep any non-boss enemy staggered). I'd rather have max barriers during that period. Besides, grenades have no cooldown and provide the best panic button. Phoenix, asari and krogan are the only vanguards I pick bonus power on (phoenix is the only one I frequently use; the other two make once in a blue moon appearance).
Cyclonic is wasted on a drell. On gold and above, there are a lot of enemies that take down drell shields in a couple of seconds (even with cyclonics). Adrenaline is the best gear for a drell and speed gives the drell more survivability than ~400 extra shields. I don't take 6b evo in fitness (the speed boosting evo), so I use adrenaline to somewhat make up for it.
Disruptor primes on all defense layers, unlike incendiary - more combos. Moreover, the tech burst resulting from DA + charge will remove shields/barriers of most enemies setting them up for a nice melee finish. AR omni blade gives only 25% melee boost unlike the shotgun variant, so I want to soften up enemies as much as I can.