nah
i dont know what it is but whenever a driver uses heavy weapon with good dmg (like derdrops) he lvls alot faster that he would with normal weapon
dunno if there is exp bonus or does your dmg matter really that much

yes heavy weapons get a noticeable xp bonus

interesting

Once I was in a game in which we did from the mid twenties to 71 in right around 4 hours. There was a lot of delay because of everyone switching gear and not bringing it with them so they could collect more items.

With no maze a group of us did 15-71 in under 4 but I don't really recall how much faster.

8 Hours ><

3h51

So you average 2 minute 54 second levels from 1-71? I doubt this very much.

Go and doubt that You not being able to believe this just shows, you need play in a real team once maybe

I solo in catas from 1-71 in about 25/30 minutes.

Don't know what's slowing you guys down so much...