Please reroll weapon dmg. Discipline is only a marginal overall dmg increase, while wep dmg is a lot stronger and stays consistent without dropping. One vault takes out everything you rerolled into if you opt for discipline. +2 discipline reroll should be reserved for when you are maximising out your stats, not trying to obtain a viable weapon.
The simulation I did for my gear with UE and 84 disc yields me ~1.74% dmg increase versus for another +2 discipline, versus ~4,1% dmg increase for 1440-1860 wep dmg. Obviously you'll need to get lucky to get high weapon dmg but it's overall worth more than +2 disc.
You two are way around this. 2 discipline = around 2.4-3% , depending on your total discipline, while with the bow the guy has, if he re-roll base damage, he can get a maxim of 3% . 4.1% or lol, 8% is just not real in this situation , because max he can get from the base weapon damage is around 100.
2 discipline is not worth it. it would be worth it if you gained 12, not 2.
84 to 86 disc 2.4% damage increase.
rerolling the base damage you can get up to 3.4k, which i think is more than 2.4%. something like 6-7% damage increase(this number might be wrong, but its definitely higher than 2.4%).
edit: 3.4k is closer to 8% damage increase. please tell me you didnt get 12 disc. and please get another bow with higher secondary
Now , is a matter of tastes , but I would choose discipline. It has more value because of the set, then base weapon damage. I however, recommend you to .. choose whatever, since you will change that weapon because of the .. somehow weak the legendary bonus.